A Python package to control Brother QL label printers. It implements the raster language of those printers and allows you to send instruction files to your printer. In more details, the following is possible with this package:

• Create raster language files for the Brother label printers. They can be created from image files or programmatically in your own Python script.
• Print raster instruction files with your Brother label printer via different backends:
  • pyusb (works cross-platform)
  • network (works cross-platform for WiFi/Ethernet-enabled printers)
  • linux_kernel (works on Linux only; uses the /dev/usb/lp0 device handles)

The following printers are claimed to be supported (✓ means verified by the author or by contributors):

• QL-500 (✓), QL-550 (✓), QL-560 (✓), QL-570 (✓), QL-580N, QL-650TD, QL-700 (✓), QL-710W (✓), QL-720NW (✓), QL-800 (✓), QL-810W (✓), QL-820NWB (✓), QL-1050 (✓), and QL-1060N (✓).

The new QL-800 series can print labels with two colors (black and red) on DK-22251 labels.

Note: If your printer has an 'Editor Lite' mode, you need to disable it if you want to print via USB. Make sure that the corresponding LED is not lit by holding the button down until it turns off.

If you're interested in printing labels using a web interface, check out brother_ql_web, which builds upon this package.

The special feature of this package is that no printer driver is required for it to work. This software bypasses the whole printing system including printer drivers and directly talks to your label printer instead. This means that even though Brother doesn't offer a driver for the Raspberry Pi (running Linux on ARM) you can print nicely using this software. And even if there are drivers for your operating system, many programs have difficulties to set the page sizes and margins for the labels correctly. If you want to print with high precision (which is important for barcodes for example), you rather want to have control about every single pixel to be printed. This is where brother_ql comes into the game.

brother_ql is available on the Python Package Index to be installed with pip:

pip install --upgrade brother_ql

The upgrade flag makes sure, you get the latest version of brother_ql but also of its dependencies.

Alternatively, you can install the latest version from Github using:

pip install --upgrade https://github.com/pklaus/brother_ql/archive/master.zip

This package was mainly created for use with Python 3. The essential functionality, however, will also work with Python 2: the creation of label files.

In order to run the brother_ql command line utility, the directory it resides in needs to be in the PATH envirnoment variable. On some systems, the pip install command defaults to the --user flag resulting in the utility being put in the ~/.local/bin directory. On those systems, extending the path variable via export PATH="${PATH}:~/.local/bin" is needed.

The main user interface of this package is the command line tool brother_ql.

Usage: brother_ql [OPTIONS] COMMAND [ARGS]...

  Command line interface for the brother_ql Python package.

Options:
  -b, --backend [pyusb|network|linux_kernel]
  -m, --model [QL-500|QL-550|QL-560|QL-570|QL-580N|QL-650TD|QL-700|QL-710W|QL-720NW|QL-800|QL-810W|QL-820NWB|QL-1050|QL-1060N]
  -p, --printer PRINTER_IDENTIFIER
                                  The identifier for the printer. This could
                                  be a string like tcp://192.168.1.21:9100 for
                                  a networked printer or
                                  usb://0x04f9:0x2015/000M6Z401370 for a
                                  printer connected via USB.
  --debug
  --version                       Show the version and exit.
  --help                          Show this message and exit.

Commands:
  analyze   interpret a binary file containing raster...
  discover  find connected label printers
  info      list available labels, models etc.
  print     Print a label
  send      send an instruction file to the printer

There are some global options available such as --model and --printer. They can also be provided by environment variables (BROTHER_QL_MODEL and BROTHER_QL_PRINTER).

The global options are followed by a command such as info or print. The most important command is the print command and here is its CLI signature:

Usage: brother_ql print [OPTIONS] IMAGE [IMAGE] ...

  Print a label of the provided IMAGE.

Options:
  -l, --label [12|29|38|50|54|62|102|17x54|17x87|23x23|29x42|29x90|39x90|39x48|52x29|62x29|62x100|102x51|102x152|d12|d24|d58]
                                  The label (size, type - die-cut or endless).
                                  Run `brother_ql info labels` for a full
                                  list including ideal pixel dimensions.
  -r, --rotate [auto|0|90|180|270]
                                  Rotate the image (counterclock-wise) by this
                                  amount of degrees.
  -t, --threshold FLOAT           The threshold value (in percent) to
                                  discriminate between black and white pixels.
  -d, --dither                    Enable dithering when converting the image
                                  to b/w. If set, --threshold is meaningless.
  -c, --compress                  Enable compression (if available with the
                                  model). Label creation can take slightly
                                  longer but the resulting instruction size is
                                  normally considerably smaller.
  --red                           Create a label to be printed on
                                  black/red/white tape (only with QL-8xx
                                  series on DK-22251 labels). You must use
                                  this option when printing on black/red tape,
                                  even when not printing red.
  --600dpi                        Print with 600x300 dpi available on some
                                  models. Provide your image as 600x600 dpi;
                                  perpendicular to the feeding the image will
                                  be resized to 300dpi.
  --lq                            Print with low quality (faster). Default is
                                  high quality.
  --no-cut                        Don't cut the tape after printing the label.
  --help                          Show this message and exit.

So, printing an image file onto 62mm endless tape on a QL-710W label printer can be as easy as:

export BROTHER_QL_PRINTER=tcp://192.168.1.21
export BROTHER_QL_MODEL=QL-710W
brother_ql print -l 62 my_image.png

The available label names can be listed with brother_ql info labels:

 Name      Printable px   Description
 12         106           12mm endless
 29         306           29mm endless
 38         413           38mm endless
 50         554           50mm endless
 54         590           54mm endless
 62         696           62mm endless
 102       1164           102mm endless
 17x54      165 x  566    17mm x 54mm die-cut
 17x87      165 x  956    17mm x 87mm die-cut
 23x23      202 x  202    23mm x 23mm die-cut
 29x42      306 x  425    29mm x 42mm die-cut
 29x90      306 x  991    29mm x 90mm die-cut
 39x90      413 x  991    38mm x 90mm die-cut
 39x48      425 x  495    39mm x 48mm die-cut
 52x29      578 x  271    52mm x 29mm die-cut
 62x29      696 x  271    62mm x 29mm die-cut
 62x100     696 x 1109    62mm x 100mm die-cut
 102x51    1164 x  526    102mm x 51mm die-cut
 102x152   1164 x 1660    102mm x 153mm die-cut
 d12         94 x   94    12mm round die-cut
 d24        236 x  236    24mm round die-cut
 d58        618 x  618    58mm round die-cut

Pro Tip™: For the best results, use image files with the matching pixel dimensions. Die-cut labels have to be in the exact pixel dimensions stated above. For endless label rolls, you can provide image files with a pixel width as stated above. If you provide a file with different dimensions when creating an endless label file, it will be scaled to fit the width.

There are multiple backends for connecting to the printer available (✔: supported, ✘: not supported):

Notes:

1. The network backend doesn't support reading back the printer state, currently. Failure such as wrong label type or end of label roll reached won't be detected by this software.
2. The label printer should show up automatically as /dev/usb/lp0 when connected. Please check the ownership (user, group) of this file to be able to print as a regular user. Consider setting up a udev .rules file.
3. PyUSB is a Python wrapper allowing to implement USB communication in userspace.
   1. On Linux: install libusb1 as offered by your distribution: sudo apt-get install libusb-1.0-0 (Ubuntu, Debian), sudo zyppe in libusb-1_0-0 (OpenSUSE), sudo pacman -S libusb (Arch).
   2. On Mac OS: Install Homebrew and then install libusb1 using: brew install libusb.
   3. On Windows: download libusb-win32-devel-filter-1.2.6.0.exe from sourceforge and install it. After installing, you have to use the "Filter Wizard" to setup a "device filter" for the label printer.

For a long time, this project provided multiple command line tools, such as brother_ql_create, brother_ql_print, brother_ql_analyze, and more. The overview of those tools can still be found in the LEGACY documentation. The use of these tools is now considered deprecated and they will be removed in a future release.

This software package was written by Philipp Klaus based on Brother's documentation of its raster language and based on additinal reverse engineering efforts.

• Philipp Klaus
  philipp.l.klaus@web.de

Many more have contributed by raising issues, helping to solve them, improving the code and helping out financially.

There are many ways to support the development of brother_ql:

• File an issue on Github, if you encounter problems, have a proposal, etc.
• Send an email with ideas to the author.
• Submit a pull request on Github if you improved the code and know how to use git.
• Finance a label printer from the author's wishlist to allow him to extend the device coverage and testing.
• Donate an arbitrary amount of money for the development of brother_ql via Paypal.

Thanks to everyone helping to improve brother_ql.

• The source code and issue tracker of this package is to be found on Github: pklaus/brother_ql.
• The package is also to be found on the Python Package Index PyPI: brother_ql.
• A curated list of related and unrelated software can be found in this document.