brother_pt

Related blog post. This is work in progress...

A Python package to control Brother PT label printers. This library implements the raster control set those printers and allows to configure these printers.

In particular, the following is supported:

• Raster image files for direct printing on TZe tape, heat-shrink tube is still work in progress
• You can print image files directly from a Python script
• Supported backends
  • pyusb
  • Planned: linux kernel usblp backend
  • Planned: Bluetooth

The following printers are supported by this package (✓ means verified by the author):

• PT-P710BT (✓)
• PT-E550W
• PT-P750W

Planned (not officially supported yet)

• PT-P900
• PT-P900W
• PT-P950NW
• PT-P910BT
• PT-H500
• PT-P700
• PT-E500
• PT-P300BT

Background

Although Brother provides support for modern Linux versions for these printers, binary drivers are required. As such the supported platforms are limited to desktop machines.

Further, the companion application does not seem to support direct raster print (iPrint and Label). In particular the software scales imported logos and image files with anti-aliasing when scaled, the printer driver then tries to use dithering to approximate these smooth edges resulting in poor print qualities of image files printed by these tools. By accessing the raster command-set directly, though this module, one can achieve higher print quality by exploiting the high resolution print modes (180x180dpi so far supported) by these printers.

This package was inspired by brother_ql and pt-p710bt-label-maker. The former provided the architectural design queues for this module, the latter provided a good initial reference for the command set used, though the provided functionality was severely limited.

The full documentation of the raster command set used by the above printers can be found here.

Installation

pip install --upgrade git+https://github.com/treideme/brother_pt.git

Usage

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

    Usage: brother_pt [OPTIONS] COMMAND [ARGS]...
    
      Command line interface for the brother_pt Python package.
    
    Options:
      -p, --printer <SN>              Serial number of a connected printer
      --debug
      --version                       Show the version and exit.
      --help                          Show this message and exit.
    
    Commands:
      discover  find connected label printers
      info      list available labels, models etc.
      print     Print a label

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_pt print [OPTIONS] IMAGE [IMAGE] ...

  Print a label of the provided IMAGE.

Options:
  -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.
  --no-cut                        Don't cut the tape after printing the label.
  --margin                        Print margin 
  --help                          Show this message and exit.

Author

• Thomas Reidemeister

Contributing

There are many ways to support the development of brother_pt:

• File an issue on Github, if you encounter problems, have a proposal, etc.
• 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.