Oils and Pigments - 2012 - Jan Esmann
Oils and Pigments - 2012 - Jan Esmann
Oils and Pigments - 2012 - Jan Esmann
By Jan Esmann
http://janesmann.com
http://www.facebook.com/jan.esmann
Jan Esmann has been a professional full time artist since 1990.
He has a B.Sc in Art Restoration from the Royal Academy of Art, Copenhagen, and and MA
in History of Modern Culture from Copenahgen University. He trained with the late Danish
artist Niels Hermann Wamberg 1980-83.
Jan Esmann
Model on chair 1 (Rune)
Oil on canvas, 2011
130 x 100 cm
colours in this slimy oil will of course produce more stable tubecolours, but they will also
have a larger oil content. Rheologically, there is no advantage to this while painting. Perhaps
on the contrary.
One way to judge if a tube contains a regular amount of pigment is to have some idea
about the weight of the pigment. Know that organic pigments are generally lightweight and
nonorganic pigments are generally heavyweight (ultramarine and lamp black being
exceptions). So if your tube of cobolt blue or ceruleum blue does not feel distinctly heavy in
your hand, compared to for example quinacridone, reject it promptly. This is difficult with
the small 38 ml tubes, but easier with large tubes.
These pigment classes are heavy: cobolt, cadmium, zinc, iron (mars), manganese
and of course the obsolete lead colours. Earth pigments are medium weight and thus difficult
to judge, but since earth costs about the same as oil, there is no need to worry too much about
earth colours. Even more so that the earth colours have much the same hue as darkened oil,
especially burnt sienna. Anyone who has compared the weight of a homemade zinc white
with a commercial zinc white will be shocked by the weight and pigment density of the real
thing. This is also because a zinc white must be ground several times, each time adding more
pigment. Commercial manufacturers do not have the patience to do that, so they grind it once
or twice and add a plasticizer.
Artist! Grind your own zinc white! Grind zinc white in alkyd or poppy or walnut oil,
all with siccative. Dont grind your lead, cadmium or cobolt colours, because they are
poisonous. If you insist on doing so, wear a mask over your mouth and nose.
3. You can not trust that the oil used is the best oil for the pigment
Most colours should be ground in linseed oil. However the whites and blues could be ground
in either alkyd, stand, walnut or poppy oil, because these oils yellow less or, rather, at least
more slowly. These oils dry slowly, so they need an addition of siccative to accelerate the
drying rate. Some respected companies market a zinc white ground in safflower oil, which is
nice considering that it yellows more slowly, but because they do not add siccative, the
colour needs about a month to dry, hence it is useless. Also safflower oil is not recommended
since it has a tendency to turn soft and sticky with age. In fact I would say: shun safflower oil
like the plague.
problems when coboltoleate is ground into colours along with the pigment and oil. Probably
because the mixture with dispersed pigment and the fine mixing in the rollers keep the oleate
dispersed and suspended enough. There is a third cobolt siccative, cobolt carboxylate, which
can be distinguised from the two other cobalt siccatives by not being violet but blackish
brown. Its use and behavior is similar to coboltnaptenate because it is diluted in mineral
spirits or similar solvent. It does not have an odor like coboltnaphtenate. Dont be concerned
about the violet hue because it will fade away within a week or so, even from blanc fix.
Siccatives are sold diluted and the concentration is usually adjusted so that normal
linseed oil paint will dry within a day if you add about 2-5% of the amount of paint (2%
cobolt naphtenate, 5% cobolt oleate). However you cant trust the label on the bottle in this
respect. I wasted my money on a flask of cobolt carboxylate siccative from Rubens that
claimed 1% was enough, however a zincwhite required 10% to dry as rapidly as with 2% of a
coboltnaphtenate from Roberson, which claimed 2% was appropriate. Dont trust a cobolt
siccative that is not dark and non-transparent you will need too much of it in your paint so
that its diluents will become a nuisance by thinning your paint to a useless amount. Some
colours require much more depending on the pigment and oil. In average linseed oil colours,
add a few drops for an amount of paint equal to a lump of sugar (about a cubic centimetre).
Slow drying pigments, like zincwite or ultramarine, ground in walnut oil will need four times
as much, that is about 10-20%. If you add aluminium hydrate to the paint, it will need more
siccative because aluminium hydroxide retards drying.
When you use siccative, be aware that the paint is apt to skin dry, that is, develop a
deceptive fully dried surface film while still wet underneath. If overpainted such will be
liable to crack. If this is the case with a work you destine for immortality, either wait till its
dry throughout or scrape off the dry film and wait for the exposed wet paint to dry. If really
too much siccative is used, the paint film will remain sticky. Adequate siccative will
accelerate the drying of the surface to make it barely tacky while the body paint below also
dries and it will not form a fully dried surface film before the body paint has set, if not dried
hard (this depends on the oil used, though). Such a break point is difficult to match and
depends on the kind of oil used, so you cant trust a given pigment always requires the same
amount of siccative, because one tube colour manufacturer may grind it in safflower oil,
while another grinds it in linseed oil. Just be alert for wet paint under a dry surface and wait
with overpainting till its dried through.
Oil content
In the list of pigments are given approximate amounts of oil needed to grind 100 parts of
pigment (by volume). These amounts change if the oil changes. The thicker the oil, the more
oil you need. So poppy oil makes leaner colours than linseed oil. Stand oil gives very fat and
fluid colours. The amounts given are for linseed oil. Also the amount of oil needed changes
with the amount of water imbedded in the pigment. Pigments like ochre are hygroscopic
because they often contain some clay. This water is no problem, but it explains why measures
are only approximate. You can get rid of the moisture by heating the pigment and this will
change the oil absorption. However, it will also change the hue of the pigment if you heat too
much.
Oils
The following oils can be used to grind colours, though they are not equally good: Alkyd (oil
modified, not urethane used for varnish, it yellows), stand oil, linseed oil, walnut oil,
safflower oil, poppy oil, sunflower oil, hempseed oil, candlenut oil (lumbang oil), tallowseed
oil (stilinga oil). The most usual are linseed, walnut, poppy and safflower. In Russia they
traditionally grind in sunflower oil. However, I do not approve of sunflower or safflower oil
because they remains very tacky for a very long time after drying causing dust and dirt to
stick to your masterpieces. Safflower oil becomes sticky again after some months or a year
after it has dried to satisfaction. During the 16th and 17th century walnut was often used
alongside linseed. You can either buy the mentioned oils from a professional craftsmans
shop or buy them, at least safflower and walnut, at your local supermarket as cooking oils.
The problem buying them as cooking oils is that cooking oils may have added antioxidants in
order to ensure the oils do not jelly in the bottle. Antioxidants retard or counteract the drying
and cause your painting to remain sticky for years. So if you purchase your oil as cooking oils
check if its free from antioxidants. If it does not say so on the label, then purchase your oil in
a biologically grown brand you trust shuns additives. You should always use cold pressed
and purified oil in order to avoid contamination with yellowing and non-drying pollutants
(organic residues).You can buy linseed oil raw and as varnish in many shops, but you should
not be tempted to use these very yellow oils unless driven by immediate need since it is
neither cold pressed not purified. No matter what oil you purchase and from what brand, you
should always initially check the drying of the oil by placing a small pool, about a few square
centimetres and half a millimetre or so deep, on a piece of cellophane. Observe how long it
takes for it to dry compared to linseed oil. Make experiments with adding siccative in small
amounts to a duplicate set of test samples. Do not be lazy and avoid doing this! Only this way
can you get to know the drying rate and drying phases of various oils and various brands.
This will reveal if the oil contains antioxidants and it will teach you things about the drying
and yellowing of oils you can not learn in any other way. For example, here you will directly
see the difference in how various oils wrinkle (this is proportionate to how it will make paint
films crack).
For those of you who are too busy making masterpieces to do these tests, I can help
you by saying, that you will find that all oils in thick layers without pigment will form heavy
wrinkles upon drying, less so stand oil and alkyd. In other words: all oils, least so stand oil
and alkyd, may cause your work to develop cracks of some kind over a century or more and
I assume you intend to make immortal works, if not, then there is no reason to read all this
anyway! So when ever you can replace some of the colours oilcontent or your mediums oil
content with stand oil or good alkyd, then do so! Now that we are praising alkyd and
standoil, you will also find, when you study your samples after 20 years, that good alkyd and
standoil practically have not yellowed, while linseed oil has turned as dark as burnt siena.
Walnut oil turned orange like red ochre or mars orange and poppy turned yellow like yellow
ochre or mars yellow. Safflower and sunflower should yellow even less. Stand oil and thick
alkyds hardly change. In fact some thick alkyds may be, for all practical purposes, considered
non-yellowing, like the siccatived AH-oil sold by Kremer. Kremer also sells a siccatived oil
called Aussenlack, which defies logic and yellows very little (Kremer does not divulge its
exact nature). These two oils also do not wrinkle. As a consequence, I have begun using AH
as a medium. Here is a list of how much oils yellow in relation to each other:
Alkyd (thick oilmodified, yellowing varies)
Stand
Sunflower (try to avoid because of its bad drying)
Safflower (try to avoid because of its bad drying)
Poppy
Walnut
Linseed
Boiled linseed oil
The next thing you will observe from your tests is that all oils except sunflower and safflower
set when dry, that is, they are dry to the touch, whereas sunflower and safflower oil remains
sticky for a long time after drying and with the term dry I mean after the period when the
oil has first expanded, then contracted to form the characteristic solid wrinkles (which stand
oil and good alkyd do not form, wherefore we love them). This residual stickiness, what so
ever causes it, you certainly dont want, because it will cause your painting to catch any dust
that might settle on it, and even worse, your glazes will show a cobweb of cracks with a few
years.
In short: shun sunflower oil and safflower oil. Stick to alkyd and standoil when you
need thick oils. Grind in linseed as much as possible. All three dry slowly, so add cobalt
siccative. You can make very durable colours by adding 20% standoil (or non-diluted thick
alkyd, if you can find it anymore, it seems to be no longer available, once there were such
oils called GG and MM, but they are gone) when grinding the colours. If that is too thick,
grind in a mixure of walnut oil with 20% stand oil and 5% siccative. The reason for adding
stand oil is that thin oils tend to make more brittle films in time, and it is my belief, that
adding a bit of stand oil can counteract this. Paint ground in stand oil makes the most durable
and tough of all paintfilms but it is only to be used for very special applications since it is
extremely thick and impossible to brush. Alternatively add stand oil, or thick alkyd, in your
painting medium.
One way you can identify which oil has been used in a commercial tube is smell and
also the colour of any free oil that may have settled at the top. You can do this test in the shop
before buying. The colour can be seen in tubes of titanium white or zinkwhite, or if the tube
has a white cap. Sunflower and safflower oil often have a slight pinkish colour. Sunflower oil
more so. Sunflower oil is quite odorless, while safflower oil has a nutty odor. Other oils are
colourless. Linseed oil has a somewhat stingy smell, while poppy oil is odorless. With these
parameters you can identify the four most common oils. The smell of linseed oil is very
characteristic. This is valuable to know if you want to make sure your zincwhite is ground in
a relatively nonyellowing oil and you want to have a hunch about how much siccative may be
required. But the again, you never know if siccative has been added. So
Always test the drying rate of an untested tube of a new colour by placing a blot of it
on a nonabsorbant surface like the top of the tube itself. Making the test here will also help
you know what really comes out of the tube, because printed labels are usually far out.
Oils can be preprocessed in order to make them more viscous or make them dry
faster. Normaly this is a matter of oxidizing or boiling with or without added driers. If you
boil an oil without access to oxygen, you get modern stand oil which is superior in every
respect except that it dries slowly. Boil an oil with access to oxygen (boiled oil), and you get
an oil that dries rapidly, yet yellows faster.
The following common oils can not be used: olive oil, castor oil, corn oil, because
they are nondrying. The industry uses other oils that the artist can not use: tung oil, perilla oil,
cottonseed oil, fish oil. Dont grind your colours in any of these colours, even though the
paintindustry uses them, because they need expert preprocessing in order to dry properly and
because they will darken. Boiled castor oil is available and it dries very slowly and yellows
slowly, though in the end just as much as walnut oil. Also dont use any kind of commercial
varnish because they most likely yellow or become brittle. Some use pure castor oil as a
plasticizer because it never dries and is nonyellowing, but this practice is dubious since any
added nondrying oil will wander through the paintlayers and cause unpredictable results. You
can make a vaselinelike drying oil by boiling linseed oil with castor oil, but its use is not
recommended because it will only hold a small amount of pigment due to its high viscosity
and will therefore yield a colour that yellows badly. If you have an electric roller mill for
grinding colours, you might use these vaselinelike oils as additives or other special purposes,
but they are impossible to handgrind to anything of practical use. However, they are not
recommended because they enhance yellowing.
Stick to Thick alkyd, stand oil and linseed oil. Of the thin oils, use walnut oil.
Grinding colours
Actually you dont need to grind your colours today, since virtually all pigments are
manufactured to very minute particle sizes. You merely need to disperse the pigment in the
oil. However, we still call it to grind colours. Proper dispersion does require some mechanical
squeezing of the oil/pigment between tight surfaces in motion, which can only be properly
done with either a muller or with electric rollers. Merely mixing with a spatula will rarely
lead to a satisfactory result: the colour will quickly appear okay, but will separate or harden
later upon storage with due cracking.
Plasticizers, such as aluminium hydrate or clay, make the final paint more short,
butter-like. If you prefer this from the raw paint is largely a matter of personal preference.
Different pigments produce very different paints and they can be somewhat homogenized
with aluminium hydroxide. A short/buttery paint will retain the brushmarks, whereas more
fluid paint tends to soften out. Adding aluminium hydrate prolongs drying.
No matter what your preference is, the proper way to grind colours is as follows:
1. Mix the pigment and oil with a large spatula on a large, thick glass plate.
2. Grind the mixture thoroughly as you can with the means you have. Be it either with a
spatula, a muller or with electric rollers (preferable because it is much, much faster). Do not
add plasticizers yet. You can add siccative to the oil in step 1 if you have experience with the
oil/pigment combination you are grinding. Otherwise follow the advice to do drying tests.
3. Cover the mixture with cellophane so it wont dry, but place a brushstroke of the paint on
some nonabsorbent surface with access to air. Leave it a day.
4. Next day (or two, depending on the desired drying time) see if your brushstroke is dry. If
not you know you have to add siccative to the paint. Also check if the large lump of paint has
become either more fluid or more stiff.
5. If the lump of pigment has changed to an undesirable consistency, either add more oil or
add more pigment. Instead of pigment you might want to add aluminium hydrate or
bentonite. If you choose to add pigment, you might have to go on ad infinitum, whereas
adding aluminium hydrate or bentonite once and for all settles the matter of consistency.
However you want to proceed, you must once more cover the paint with cellophane and leave
it a day. Remember to take notes on each pigment!
6. Once the lump of paint has the right consistency even after a day or two, it is time to
consider the amount of siccative. Check the brushstroke exposed to air and see if it is
sufficiently dried after the time you allow. Most people want their paint to dry from one day
to the next. If it is not dry, add about 2% siccative to the lump, make a fresh brushstroke on a
nonabsorbent surface and cover the lump with cellophane. Leave it a day.
7. Check if the stroke of paint is adequately dry. Adequate is a matter of taste, but be
especially careful not to be fooled by a skin dry paint. Thin paint might be dried through, but
thicker layers may only be dried on the surface while wet underneath. This is a very tricky
situation. Should one add more siccative or not? This is again a matter of taste. On the one
hand you can add more siccative to make it dry through faster, on the other hand you might
decide you have added to much already, since the paint has surface dried and not dried
through while the only thing lacking was your patience. Slow drying oils tend to skin dry no
matter what, that is: poppy oil, safflower oil, sunflower oil and to some degree walnut oil.
Polymerized oils tend to dry through, even though they may actually be slow driers, that is:
stand oil and alkyd oils. Linseed oils normally dries through unless one has added too much
siccative or unless the case is that exceptional one where the pigment is a retarder (like zink
white) and one has added sufficiant siccative.
8. The general rule is: first grind the pigment and the oil. Then wait a day and decide if you
need plasticizers and/or siccatives. Also: make notes! Grinding colours is an individual
matter and while one grinds colours to a very stiff paste another might like them more fluid,
so no set formulas can be given about hand making of colours except that, if made with
diligence, they surpass any commercial colour, because you get exactly what you want.
9. Some colours tend to be very poor in commercial tubes, so they ought to be made by
oneself, especially: zink white, ultramarine violet, ultramarine blue (they should all be ground
in alkyd, walnut or poppy oil, perhaps with an addition of 10-20% stand oil for strength). In
addition one might want to grind a small number of titanium whites with distinctly different
consistency so as to be able to control the texture of the brushstroke. I will return to this
elsewhere.
It is noteworthy that when you grind your own colours they will dry up matt. Commercial
tube colours usually dry up glossy or semi-glossy. So commercial colours contain too much
oil. What is interesting about this observation that home ground colours dry up matt is that
you can use ample painting media far more than with commercial tube colours before
there is danger of an alarming excess of oil. This sheds some interesting light on old masters
technique, because we know that the paintings of Rubens dried up glossy, yet he of course
ground his own colours so they should have dried up matt. In other words he used much
medium and a medium of a glossy oil-rich kind.
Pigments
Historic use of pigments
When you look at old paintings and wonder what pigments they used, it is good to have some
knowledge of the most important pigments and when they were in use.
Up to about 1800 a special green was used: copperresinate. According to some recipies it was
made by boiling verdigris into a balsam like venetian turpentine. Other recipies mention
grinding verdigris in balsam and allowing it to dry, then scraping the dry mixture off and
grinding that in oil. It is highly transparent and only used as a glaze. It got replaced by
mixtures with prussian blue etc.
In the following pigments are ordered according to in how many paintings they were found
out of a specific corpus (1). This survey did not include copperresinate.
Up to 1500
Black:
Blue:
Green:
Red:
White:
Yellow:
1500 - 1600
Black:
Blue:
Green:
Red:
White:
Yellow:
1600 - 1700
Black:
Blue:
Green:
Red:
White:
Yellow:
Brown:
Khn, H.: Terminal Dates for Paintings Derived from Pigment Analysis, Museum of Fine Arts, Boston
Massachusets, 1973. Pp 199-205.
1700 - 1800
Black:
Blue:
Green:
Red:
White:
Yellow:
Brown:
1800 - 1900
Black:
Blue:
Green:
Red:
White:
Yellow:
Brown:
List of pigments
In the following list pigments are classified as good, acceptable and bad. This partly follows
ASTM standards I, II and III. The reason for not quite following it is that ASTM concerns the
pigment alone and we are specifically interested in oil ground pigments. ASTM I is
permanent and lightfast in all techniques and even in fine tints. ASTM II is acceptable, but
faint tints may fade. ASTM III is the permanence of Alizarin, which actually is not
adequately lightfast to be used in works destined for immortality. Even though a pigment in
itself may be ASTM I, it may be classified as acceptable, not good, if it tends to darken in oil,
like Prussian blue does, or if it contains so much oil it is prone to wrinkle upon drying and
make overpaints crack, like carbon black.
Blue
Good
PB 15
PB 15:6
PB 16
PB 22
PB 28
PB 29
PB 33
Technical Bulletin of the National gallery, London, vol 18, 1997, pp 6ff.
blue and cerulean blue, though it will be a bit darker and will have a higher oil
content, about 60%, so it will probably be more likely to yellow. This latter
mixture will also be more expensive.
PB 35
Ceruleum, Bleu Celeste. Oxides of cobolt and tin. Very expensive. Weak tinting
strength. Medium dryer. 120-140% oil. Because of the high oil content it should
only be ground in low-yellowing oils like alkyd, poppy or walnut. This is a
strikingly beautiful blue, hard to emulate. It can be replaced by a mixture of
ultramarine, phtaloblue and some zink white (titanium white will make it more
opaque than the original product). This mixture also emulates the relative
transparency of ceruleum and can be manipulated to any of the many shades
ceruleum comes in. Since ceruleum blue requires so much oil it is wise to
dispense with it or only use it in overpaintings. The suggested mixture will only
contain about 40% oil and is much cheaper, so it is a wiser choice. Mix it and fill
a tube with it. If you really need the nice skylike hue and texture of ceruleum,
then so be it, but grind it yourself in a low-yellowing oil. Remember that for any
blue to contribute to the immortality of your work, it should have a low
oilcontent, because otherwise it may turn greenish upon ageing. Certainly dont
use it with oil rich painting mediums like gelmediums. If you grind it yourself,
know that some sources claim it will harden after a few days, so first grind it, then
leave it covered to see what happens and add more oil accordingly. Doerner for
this reason recommends 2% wax in the oil. Personally I have only experienced a
separation in the tube so the oil would flow out when you remove the cap from
the tube. Large amounts of aluminiumhydroxide might counteract this, but 2%
aluminiumstearate would probably be wiser. The best, of course, is not to care
about the excess oil and simply allow it to flow out on an old newsparer without
further ado. If the colour itself is too soft, leave it on the newspaper awhile to
remove some of the oil.
PB 36
PB 60
PB 74
Ceruleum. Dark oxides of cobolt zinc silicate. See notes for PB 35, PB 28.
Acceptable
PB 17:1
PB 27
Prussian Blue, Berlin Blue, Paris Blue, Milori Blue. Ferri ammonium
ferrocyanine. High tinting strength. Transparent. Fast dryer.
It may be emulated by a mixture of phtaloblue, ultramarine and black or
phtaloblue, dioxazine and black. Since it requires up to 120% oil, it is prudent to
replace it with this mixture when used pure or for underpainting. If not for any
other reason, replace it because its permanence is dubious, though authorities
seem to differ in this respect. Its tendency to become dull may be because of its
high oil content.
Bad
PB 1
PB 24
PB 66
Indigo blue.
Miscellaneous blues
Academy Blue: Ultramarine + viridian.
Cyan:
Coboltblue + prussian blue.
Pure blue: Coboltblue + manganese blue.
Traditional blues
PB 29
PB 30
PB 31
PB 32
---
Black
Good
PBk 8
Charcoal. Vine black. Blue black. Semi transparent. Cold and slightly grayish.
Very slow drier. 50-120% oil.
PBk 9
Ivory black. Burnt animal bone. 50% oil. Inexpensive. Slow drier. If used as an
underpaint it will cause overpainted layers to crack badly. Do not use as an
underpaint unless mixed 1:1 with pigments or fillers of low oilcontent - or mix
1:1 with manganese black or mars black. Can be used as a glaze, though the
pigment is strictly speaking not transparent.
PBk 10
Graphite gray.
PBk 11
Mars black. Ferro-ferric oxide. Cheap. Very opaque black. Good for
underpainting. 40-50% oil. Medium drier. Good tinting strength. If one requires
black in either the ground or underpainting, then manganese or mars black are the
best choices.
PBk 14
PBk 19
PBk 26
Acceptable
PBk 6
Lamp black, blue black, carbon black. Requires a huge amount of oil from 100800% depending on the particle size - so though it is a permanent colour, its use
in oil is unwise. It practically never dries and tends to wrinkle. If used as an
underpaint, layers above it will crack badly. It is best to mix it 1:1 or 1:3 with
manganese black or mars black, but then again, why not simply stick with
marsblack? There is really no need for lamp black unless you want deep black
glazes since it is the blackest of all the blacks. In use since about 1885.
PBk 7
PBk 19
Slate grey, Davys grey. Powdered slate. Medium to dark gray colour.
Bad
PBk 1
Aniline black.
Miscellaneous blacks.
Paynes grey: Ultramarine + lamp black + slate + iron oxide red.
Davys grey: Powdered slate.
Here are some of my own favourite mixtures:
Opaque grey: Chromium oxide + caput mortuum/mars violet. This grey is for when you
either need to cover an underpaint with a grey or when you need a grey in your
opaque lights and really need to preserve opacity.
Transparent grey: 8 parts azomethine yellow, 4 quinacridone, 1 phtalocyanine. Proportions
vary depending on the brand used and upon what hue you need. This grey you
should adore and dream about at night. It will serve your shadows like nothing
else.
Neutral grey: 3 ultramarine + 1 umber (burnt or raw). This is my standard grey. It is cheap,
semitransparent and also dark, yet bright, enough to serve as a black in most
cases.
Brown
PBr 6
Reynolds recommended a mixture of indian red and black for the underpainting,
but here mars brown might do equally well (or vice versa) if you want to emulate
this old English masters technique.
You could substitute mars brown with burnt iron oxide black if you possess
the iron oxide black pigment and desire to do the roasting yourself. Roasting
pigments can be done by placing the pigment in a thin layer on a metal plate, like
a cleaned lid from an empty can of paint, and then heating it above a flame or on
a stove. You can get very beautiful roasted ochres this way, but strong heating
can not be done on an electric stove because you need the greater heat of a direct
flame. Remember to stir the powder so you dont just roast the bottom layer and
leave the top unchanged. On the other hand such mixtures can be truly beautiful,
though hard to reproduce next time you do the roasting.
PBr 23
PBr 24
PBr 25
Benzimidazolone
Other browns
PY 42
Mars yellow. See below.
PY 43
PBk 14
Manganese brown. 30% oil. Opaque. Good drier. It resembles mars brown but is
slightly colder when mixed with white. It has somewhat the mass colour of a pale
burnt siena, though not sienas glow when glazed. Its difficult to glaze with
manganese brown. It is also cold when mixed with white, where burnt siena is
warm. Use this intense pigment when you need brown in your underpainting or
cold brown greys. You will have to grind it yourself since it is not readily
available in tubes. See manganese black. Harmful, so dont breathe dust.
PG 23
Burnt green earth. 80% oil. Resembles a mixture of burnt umber and burnt siena.
Can with advantage replace burnt siena in many cases, because it contains less oil
and darkens less.
Acceptable
PBr 7
Burnt and raw umber and burnt and raw siena. Good driers. Semi-transparent.
The umbers and the sienas darken with age (even within a relatively short
time, that is 10-20 years) because of their large oil content. It is therefore
advisable to grind ones own using good alkyd (most alkyd is thicker than linseed
oil), poppy or walnut oil. Some umbers need an addition of a plasticizer in order
not to settle or jelly in the tube, but I have observed that one brand of raw umber
did not change, while an other brand stiffened in a few weeks and had to receive
additional oil. Probably this difference stems not from the umbers, but from the
prescense of clay or chalk. Traditionally one recommends 2% wax or
aluminiumstearate melted into the oil. Kurt Wehlte recommends substituting
umbers with mixtures based on burnt siena in order to reduce the oil content (and
avoid subsequent darkening), but this seems ill advised since burnt siena requires
even more oil than the umbers. Replace them with mixtures based on manganese
brown or mars brown. Burnt siena can often be replaced with burnt green earth.
Sienas
Burnt siena requires up to 200% oil which means it will darken with age as the
oil turns brown. Raw siena requires up to 120%, so it will also darken somewhat.
Do not use pure siena for underpainting since it will cause overpaints to crack. If
you need pure burnt siena as a heavy glaze or as an underpaint, you can emulate
the colour with a mixture of azomethine yellow (PY 153), quinacridone and
black, though this is more expensive. For underpainting you can replace it with
mars brown or manganese brown, for glazes add azomethine yellow to the
mars/manganese brown.
If you run out of raw siena and have an immediate need, you can make an
ochre (or mars yellow) look like raw siena by adding burnt siena (or mars brown)
and adjusting with a bit of green or blue. Since raw siena darkens a lot, it is wiser
to use this substitute which will have half the oil content. If you grind your own
colours, mix a raw siena substitute from mars colours and chromium oxide green.
Umbers
You strictly speaking dont need both raw and burnt umber of the type
commonly available on tube by various manufacturers. Common (warm) raw
umber can be made to look like burnt umber by adding either benzimidazolone
red (PR 175) or nickel azomethine red (PO 65) or alizarin. You can make burnt
umber look like raw umber by adding a bit of chromium oxide green (phtalo
green will not do) and adjusting with ochre.
What you want is a major difference between your raw and burnt umber. I
have come to the conclusion that the ideal combination of umbers is to choose a
green raw umber and a violet burnt umber. The burnt umber should become cold
when mixed with white but remain warm when used pure as a glaze. Raw umber
should become grey when mixed with white, and when used pure as a glaze it
should have a cool brown-grey effect so beautiful in shadows. This difference
between burnt and raw is unfortunately seldom encountered in ready made tubes.
So, artist, grind your own umbers! Make a violet burnt umber and a greenish raw
umber and you will be well on your way to becoming a colourist and clairobscure master all at once.
The umbers are often recommended for underpainting, but are actually not a
technically good choice if used pure and solid because they contain about 100%
oil or more. One can overcome this by mixing the umbers 1:1 with zink white
or blanc fix (PW 21), which may reduce the general oilcontent to about 60%.
Using blanc fix will hardly change the colour of umber but will make it more
transparent, which can be desirable in the underpainting, though this has other
drawbacks. Adding too much black fix is problematic because the pigment is
transparent in oil and though it reduces the average oil/pigment ratio, it raises the
amount of oil that the actual pigment (the umber) has to hide, thus enforcing
yellowing. This might not be a problem when underpainting, but certainly when
overpainting. So what to do?
Perhaps the best is to grind umbers (and sienas) in walnutoil and add 20%
stand oil this oil mixture needs 10% coboltlinoleate siccative, even with
umbers. This mixture, I believe, will counteract the deficiencies of the various
oils (stand oil counteracts the tendency to become brittle with age, that the other
oils show), and this mixture certainly will yellow less, or at least much slower,
than linseed oil. Probably it is the best mixture to grind all colours with. More
research on the subject is required. Please consult the sections on grinding colours
and on oils for more technical details.
Bad
NBr 8
Van Dyke brown. Genuine Van Dyke brown is rarely sold in tubes today and
thank God for that since the colour is not lightfast. They usually contain a mixture
based on umber. Some insist on using the true pigment for underpainting
following the so called 19th century brown sauce of traditional academy
painting used for laying in shadows. This is a bad idea because Van Dyke brown
contains 250% oil and will cause the overpaint to crack. If used for glazes, the
painting will darken much upon age. Avoid it. The brown sauce of the
academicians of the 19th century was a red-brown colour easily mixed by
several colours (try burnt umber and earth red for one).
PBr 8
Traditional outdated
NBr 9
Sepia. Not usefull in oil. It was used for brown semitransparent inks. Under this
name is sold a number of browns mixed from umber and other earth colours. The
original colour fades in all mediums.
---
---
Bister. Yellowish greybrown soot with some woodtar. Today various permanent
brown mixtures based on umber is sold under this name.
Green
Good
PG 7
Phthalocyanine green. Monastrial green, phtalo green. Very high tinting strength.
Very transparent. 30-45% oil. Medium to slow dryer. Can be used to emulate the
more expensive viridian (PG 18). Available since about 1940.
PG 10
Nickel-azo, Green Gold. Quindo green gold. 35-40% oil. (see PY 150). Very
slow drier. Extremely transparent and strong colour. Irritates nickel allergy.
Medium to slow drier.
PG 17
Chromium oxide. 30% oil. Very opaque. Good tinting strength. A peculiar dull
green, that is neither yellowish nor blueish. Inexpensive. Medium dryer. This is
one of the most opaque colours we have and as such it can not be emulated. The
hue of chromium oxide green can be emulated with a mixture of phtalogreen, raw
umber and titanium white. It is more transparent than the real thing. You can also
emulate chromium oxide green with phtalogreen, mars yellow, mars black (or
manganese black) and titanium white. The choice of pigments in this mixture
reflects an urge to use the most opaque substitutes. You could use raw siena,
ivory black and zink white instead if you want a semitransparent version. Because
these emulations are more transparent than the real thing, you can make some
nice scumbles on flesh with them. Discovered 1797. In use since about 1865.
PG 18
PG 19
Cobolt green, Rinmans green. Oxides of cobolt and zinc. 70% oil. Expensive.
Weak tinting strength. Semi opaque.
Cobolt green can be emulated with a mixture of phtalogreen, siena and zink
white. Depending on the particular shade of cobolt green you want, you can use
either raw or burnt siena. You can also emulate it with ultramarine, viridian and
black.
Because of cobolt greens high oil content and high price, you will probably
want to use a substitute and will, in case you fancy it, benefit from having it
premixed in a tube. Remember, though, that it is often better to do without greens
altogether, since its better to mix greens from the blues and yellows used in the
picture if greens are needed. Flesh can appear to have green tints which might
require a premixed green; here cobolt green substitutes in the tube come in handy
and there is no need for the real stuff. For foliage try to manage with greens
mixed from blues and yellows. If you have a man made green object in your
picture, like a painted cupboard, please try to manage by not trying to reproduce
its true colour, but instead approximate it with a mixture of the blue-greens and
yellows you already have on your palette. Avilable since about 1835.
When grinding, know that it may harden in the tube, so leave it a few days and
then add more oil. Doerner recommends 2% wax in the oil.
PG 23
Green earth. Natural earth. 80-100% oil. Low tinctorial power. Normal dryer.
Cheap. There are several types of green earth. Bohemian and Tirolean are warm
and transparent, Veronese is cold and a bit more opaque. The coldes varieties can
be icy green. They were much used in medeival Italian anconas as an underpaint
for flesh. Doerner notes that Bcklin and Mares used it that way too as well as
for the shadow and middle tones of flesh. Because of its large oil content and
transparent nature it will darken. It can be replaced with a mixture of ochre,
chromiumoxide green, black and white. This mixture is less prone to darkening
since it has less oil and is more opaque, but it will not be so good for glazes. If
you heat green earth you get a brown semitransparent colour, burnt green earth,
which is quite nice and somewhat resembles burnt siena, though it is not as fiery.
PG 24
PG 26
Cobolt green. Oxides of cobolt and chrome. Medium tinting strength. Fast dryer.
70% oil. See PG 19. Expensive. Can be emulated with Phtalogreen, siena (raw or
burnt depending on the shade you want) and zinc oxide.
PG 36
PG 50
Cobolt green dark. Oxides of nickel, cobolt and titanium. Medium tinting
strength. Fast dryer. 70% oil. See PG 29.
Bad
PG 1
Brilliant green
PG 2
Permanent green.
PG 7
PG 8
PG 12
Green.
Miscellaneous greens
Cadmium green. Mixture of cadmium yellow and phtalogreen. It used to be cadmium yellow
and either ultramarine or viridian. Slow drier.
Emerald green, vert emeraude, schweinfurt green. Traditionally this was copper acetoarsenite, which is toxic and impermanent. Under this name is now sold a variety
of intense, light, cold greens. You can mix your own emerald green from
phtalogreen, azomethine yellow (PY 153) and titanium white.
Chrome green, vert anglais. In the 19th century this was chrome yellow + prussian blue, not
chromium oxide as today. Chrome yellow is impermanent. Some odd mixtures
exist today, but most of them are too saturated and pure hued because they are
based on the cheap phtalocyanine green and hansa yellow. You can easily
emulate the beautiful earthly hue of the original chrome greens. Chrome green
light can be emulated with cadmium yellow light (not lemon) and chromium
oxide green (not viridian nor phtalogreen). Crome green dark can only be
emulated by prussian blue and cadmium yellow light (or dark, depending on the
hue).
Zink green, Zink yellow + prussian blue. Obsolete.
Verdigris, Copperacetate. Toxic. Obsolete.
Malachite. A natural green. Never much used. Long obsolete.
Orange
Good
PO 20
PO 20:1
PO 23
PO 23:1
PO 36
PO 43
Perinone, anthraquinone.
PO 48
Quinacridone gold. Yellow orange, similar to burnt siena, but with higher tinting
strength. Semi-slow drier.
PO 49
PO 59
PO 60
PO 61
PO 62
PO 65
PO 67
Pyrazolochinazolon.
PO 69
Isoindolin.
PO 71
PO 73
Acceptable
PO 5
Bad
PO 1
Hansa orange.
PO 12
Chrome orange.
PO 13
PO 34
Diarlylide orange.
PO 105
Miscellaneous oranges
Academy Orange: English red + cadmium yellow.
Titanium orange. See PBr 24.
Red
Good
PR 20
PR 88
PR 101
Synthetic iron oxide in many shades. In order from warm to cold they are: light
red, english red, indian red, venetian red, mars red, mars violet (synthetic caput
mortum). 30-70% oil. Cheap. When grinding colours like english red, know that
they tend to become fluid after a week or two, then you have to add more pigment
or aluminium hydrate.
Mars violet can be emulated by a mixture of dark cadmium red and raw umber
(perhaps with a bit of black, depending on the umber), though it wont be quite as
cold when mixed with white. The mixture is of course more expensive than mars
violet.
Light red is identical to pozzuoli red.
PR 102
Burnt ochre, Light red, Antwerp red, Bolus. Calcined natural ochre. See PR 101.
PR 108
PR 113:1 Cadmium-vermillion red. Lithopone red. Expensive, Toxic. Slow drier. Opaque.
PR 119
Naphtol FG. This is the only naphtol, that is lightfast even in pale tints.
PR 122
PR 123
PR 144
PR 149
Perylene red BL. Anthraquinone red. Medium drier. Transparent. High tinting
strength.
PR 166
PR 175
PR 176
Benzimidazolone.
PR 178
Perylene red.
PR 179
PR 181
Thioindigoid magenta.
PR 190
Perylene scarlet.
PR 192
PR 194
PR 202
PR 207
PR 209
PR 214
Condensed azo.
PR 216
Pyranthrone red.
PR 254
PR 255
PR 260
Isoindolin.
PR 264
Acceptable
PR 5
Naphtol red ITR. Slow drier. Transparent. Pale tints may fade.
PR 7
Naphtol red F4HR, naphtol red AS-TR. Slow drier. Transparent. Pale tints may
fade.
PR 9
Naphtol red AS-OL, permanent red FRLL. Slow drier. Transparent. Pale tints
may fade.
PR 14
PR 106
PR 168
PR 187
PR 188
Bad
NR 9
PR 3
Studio red. Hansa red. Slow drier. Transparent. Pale tints may fade.
PR 4
PR 8
PR 12
Naphtol AS-D.
PR 17
Naphtol AS-D.
PR 23
Naphtol AS-BS.
PR 31
Naphtol AS-BS.
PR 48:1/2/3
Permanent red.
PR 49:1
Lithol red.
PR 52:2
Lithol red.
PR 53:1
Red lake C.
PR 57
Lithol rubine.
PR 57:1
PR 60
Scarlet lake.
PR 60:1
Pigment scarlet 3B
PR 81
Rhodamine.
PR 83
Alizarin Crimson, rose madder alizarin. Slow drier. Transparent. 60-75 oil.
Alizarin can be closely emulated by a mixture of dark quinacridone and
azomethine yellow (PY 153). Quinacridone and umber can sometimes do.
According to Pip Seymour (3) it may be emulated by quinacridone (PV 19),
perylene red (PR 149) and ultramarine blue. I disagree. However, an almost
perfect emulation can be made with dark quinacridone magenta, azomethine
orange and burnt umber (first mix equal parts of quindo and azomethine, then mix
12 parts of the mixture with one part of good dark burnt umber). This mixture
needs siccative. Alizarin can be somewhat replaced by paliogen maroon (PR
179); it is perfectly replaced by PR 177.
PR 87
Eosine lake.
PR 90
Phioxine red.
PR 105
Red lead.
PR 104
Chrome red/orange. Molybdated red. Toxic. Turns dark in oil. 40% oil.
PR 112
PR 114
PR 146
PR 149
PR 170
Naphtol crimson, naphtol red F5RK, permanent red F5RK. Slow drier.
Transparent. Pale tints may fade.
PR 171
Naphtol AS.
PR 173
Rhodamine.
PR 177
PR 259
Miscellaneous reds
Scarlet red. A mixture of alizarin crimson and vermillion much used in portraits in the 18th
and 19th century. Resembles cadmium dark.
Untested reds
PR 13
Toluidine Red.
PR 242
Sandorin scarlet.
PR 251
Pyrazoloquinazolone 12925.
Violet
Good
PV 14
Cobolt violet dark, cobolt phosphate. Very expensive. Weak tinting strength.
100% oil. Semi transparent.
Cobolt violet can be emulated by a mixture of manganese violet and zink
white. Alternatively use ultramarine violet, quinacridone and zink white if you
want greater control of its hue. Since the substitutes will only have about 20-30%
oil, it is wise to use them instead of cobolt violet. If you really want cobolt violets
hue, reserve it for overpainting and glazes. Available since about 1860.
PV 15
Manganese violet, manganese ammonium pyrophosphate. Semi transparent. 2030% oil. Fast dryer. Available since about 1870. Manganese violet can be
emulated by ultramarine violet and some quinacridone. When grinding this colour
know that it will become fluid after a few days.
PV 19
PV 23
Dioxazine. Carbazole violet reddish. Permanent violet RL, RS. (BS, bluish shade,
is not as permanent, but acceptable). High tinting strength. Slow to medium drier.
PV 23:1
Dioxazine.
PV 31
Isoviolanthrone.
PV 46
PV 47
PV 49
Acceptable
PV 14
Bad
PV 1
PV 3
PV 4
Magenta.
PV 5:1
Alizarin maroon.
PV 39
Untested violets
White
Good
PW 6
Titanium dioxide (rutile). Our most opaque white. Slow dryer. Inexpensive. 1520% oil. In use since about 1920.
Acceptable
PW 1
Lead white, Ceruse, Cremnitz white, Flake white. Lead carbonate. Toxic. Fast
dryer. 20% oil. Very toxic. Do not grind yourself. If you desire its
semitransparency, replace it with a mixture of titanium white and zink white (1:2)
or titanium white and black fix (1:3). Turns more transparent with age.
PW 4
Zinc white. Should be ground in alkyd, poppy or walnut to prevent (or delay)
yellowing. Slow drier. It requires siccative especially in these oils. Semi
opaque. 15-25% oil. Available since about 1835 as watercolour, but not much
used as oil colour before 20th century. If ground in slow drying oil, like poppy oil,
it requires about 10-20% siccative depending on the concentration of the
siccative. Zinc white is one of the most difficult pigments to make good colours
of, because even though ground to a stiff paste, the next day it will be thin again
and this seems to be going on day after day and again after a few weeks. For
this reason manufacturers add much plasticizer like aluminiumstearate to put an
end to this. If you grind your own zinc white, grind it again and again over three
days, then use more zinc white, or perhaps aluminiumhydroxide, to make it stiff,
wait a day and finally add some more zinc white or aluminiumhydroxide and put
it in tubes. It will still become more fluid later, but not so much. And it will be a
dense pigment, which still has the semitransparent nature of zinc white. It is much
advised to grind zinc white in good alkyd because alkyds are more flexible and
zinc white in oil produces a brittle film. It is not advisable simply to mix your
pigment with oil, because the resultant film will be weak and tend to crack in a
few days. Doerner recommends grinding zinc white with a mixture of oil and
resin in order to make it dry faster, but that would be bad. I disagree because this
will only make the film even more brittle and will not impart any good qualities
such as less yellowing. It is generally advised not to use zinc white in the
underpainting because of its slow drying. I believe there is no problem if you add
cobolt siccative in sufficient amounts and keep your underpaint relatively thin.
Zinc white becomes more transparent with age, just like lead white does, due to
saponification. For this reason it is often mixed 1:1 with titanium white, which is
a good practice also because the film will be stronger and titanium tends to be too
opaque anyhow. Zinc whites transparency can be emulated with a mixture of
titanium white and blanc fix (1:10) or titanium white and aluminiumhydroxide
1:5. The latter yellows less. Zinc white has fallen in disrepute lately amongst
restorers, because its film always cracks and for various other serious reasons I do
not readily remember.
PW 5
PW 7
Zinc sulphide.
Bad
PW 2
Lead sulphate.
PW 17
Bismuth white.
Miscelaneous whites.
PW 15
PW 18
Chalk.
PW 20
PW 22
Baryte.
PW 26
PW 27
Silica.
---
Mixed white. A usefull mixture of equal parts of titanium and zink white. In older
books its flake white and zink white.
Blanc fixe. Barium sulfate. Less transparent than aluminium hydroxide. Can be
used to manipulate transparency and oil content. 10-20 % oil. Should be ground
in alkyd, poppy or walnut oil.
PW 24
Clay
As dry powder. Clay of various types can be used as an additive to control the
rheology (brushstroke and flow) of oilpaint. Most clay contains iron, hence its
typical colour which can be a nuisance even though it is permanent. Kaolin, or
China clay, is the most colourless (white) of the clays. Bentonite is a wonderful
plasticizer, but it has the usual claycolour and will tone your colours cream. Some
recipes recommend using clay in large quantities in the ground, but this is a bad
practice since clay is hygroscopic and can hold the water for a long time with the
effect, that subsequent layers of oilpaint may eventually peel off. The use of
kaolin in the ground of van Dycks Great Peace was as early as 1676 thought to
be responsible for the paint peeling off.
Chalk
20% oil.
Gypsum
10-20% oil.
Talcum
20 % oil.
Yellow
Good
PY 31
Barium Yellow Lemon. Barium chromate. Toxic. Medium dryer. 15-20% oil.
Even more milky than nickel titanate (PY 53).
PY 32
PY 35
PY 35:1
PY 37
Cadmium yellow (medium & dark). 99,9% cadmium sulphide. See PY 35.
PY 37:1
PY 41
PY 42
Mars yellow & orange. Synthetic iron oxide. 65-70% oil. See PY 43. More
opaque than natural earths. There are specially manufactured highly transparent
ironoxides available, but they are comparably quite expensive. Grinding mars
yellow is tiresome. You can run it through the mill several times. You can add up
to 100% aliminiumhydrate (which is far too much for any pigment) and still run it
through the mill and see it become extremely fluid upon grinding, though stiff to
begin with. What to do? Replace your plasticizer with bentonite. Bentonite is a
clay with aproximately the same colour as ocher and it will for some reason serve
you better than aliminiumhydroxide or aluminiumstearate. Personally I mix a stiff
paste of oil and ochre (mars yellow) and run it through the mill, then run ochre
(mars yellow) and oil through the mill an extra time, adding more ochre (mars
yellow) and bentonite (1:1) each time. On the third run I add enough pure
bentonite to make the paste very stiff, then run the stiff paste through the mill and
do with the result.
PY 43
Natural ochre, chamois, yellow/brown ochre. 50-60% oil. Semi-opaque. Semislow drier. About grinding see PY 42. If you run out of yellow ochre and have an
immediate need, you can mix it from raw siena and cadmium yellow or chrome
titanate (PBr 24), this is a waste of money. Likewise, you can make an ochre look
like raw siena by adding burnt siena and adjusting with a bit of green or blue.
Regarding grinding, see PY 42. Use ochres instead of raw siena when ever
possible.
PY 46
Lead-TinYellow. Lead stannate. Toxic. Fast drier. 30% oil. Low tinting power.
This is probably the Giallorino of the Italian rennaisance. It was the most
common yellow up until the 17th century then from about 1650-1750 it became
replaced by naples yellow and ultimately forgotten, only to be rediscovered by
restorers at the middle of the 20th century. It is not needed anymore because we
have the safer nikkel titanate yellow (PY 53), which, if you add equal amounts of
titanium white, very much resembles the cold pale variety of lead-tin yellow (type
I). The warm darker variety (type II) can be emulated by nikkel titanate yellow,
ochre and white. The dark variety is what Rembrandt used to imitate gold. The
pale yellow light in his pictures stems from pale lead-tin yellow. PY 46,
strangely, also refers to massicot (litharge, lead mono oxide), which undoubtedly
is what some Italian rennaisance writers call giallorino.
PY 53
PY 65
Arylide yellow, hansa yellow RN, permanent yellow RN. 50% oil. All hansa
yellows are semi transparent and very slow driers. They come in a variety of
shades. Available since about 1915.
PY 73
Arylide yellow, hansa yellow GX, monoazo yellow, permanent Yellow GX. 50%
oil.
PY 74
Arylide yellow, hansa yellow 5GX, monoazo yellow, permanent Yellow 5GX.
50% oil.
PY 83
PY 97
PY 98
PY 108
PY 109
Isoindolinone G. Tetrachloroisoindolinone.
PY 110
PY 112
Flavanthrone. An orange-yellow.
PY 119
PY 120
Benzimidazolone yellow.
PY 128
PY 129
PY 138
Quinophtalone.
PY 139
PY 150
PY 151
PY 153
PY 154
PY 156
PY 157
Priderite yellow. Nickel barium titanium primrose. Slow drier. Opaque with
medium tinting strength.
PY 175
PY 184
Bristol yellow, sicopal yellow. Bismuth vanadate. Opaque. Good tinting strength.
Full range from light yellow to reddish hues. Available since the 1980s.
PY 216
Acceptable
PY 3
Arylide yellow, hansa yellow 10G, monoazo, permanent yellow 10G. 50% oil.
Bad
PY 1
Arylide yellow, hansa yellow G, monoazo yellow, permanent yellow G. 50% oil.
PY 12
PY 13
PY 14
PY 17
PY 20
Benzidine yellow B.
PY 34
Chrome yellow 5GH. Lead chromate. Turns dark and greenish. 30-60%
oil.Lemon to orange shades. Opaque. Fast drying. Invented 1797, in use since
about 1940.
PY 36
PY 40
Aureolin, cobolt yellow. Cobolt potassium nitrite. Expensive. Slow drier. 30-40%
oil. Semi transparent. Available since about 1850. You dont need this colour,
because you can exactly duplicate its hue and transparency with a mixture of
azomethine yellow (PY 153), a small amount of chromium oxide green (not
viridian or phtalogreen) and some zink white. If you dont have chromium oxide
green, you can approximate aureolin by substituting chromium oxide green with
ultramarine blue or ultramarine violet, though it wont be an exact match.
PY 55
PY 100
Tartrazine yellow.
PY 182
Untested yellows
PY 73
PY 75
PY 81
Traditional yellows
PY 39
PY 46
NY 24
---
Indian yellow. Illegal since 1920s. Made from the urine of cows on a painful diet
of mango leaves. Can be replaced by nickel azo green-gold (PG 10). Some
replace it with aureolin (PY 40).
---
Jan Esmann
Open face (Johanne)
Oil on canvas, 2011
130 x 100 cm
Jan Esmann
Open face (Julie)
Oil on canvas, 2010
130 x 100 cm
Jan Esmann
Open face (Kirstine, I)
Oil on canvas, 2010
130 x 100 cm