qlprint

Command-line utility for printing to Brother QL series label printers.

Tested with:

• QL-570

Hopefully also works with:

• QL-500/550
• QL-560
• QL-580N
• QL-650TD
• QL-700
• QL-710W
• QL-720W
• QL-1050
• QL-1060N

Inspired, though not derived from, the ql570 tool. Licensed under the GPLv3 nevertheless.

Building

Requires GNU make and libpng (with development headers), with pkg-config to locate libpng headers & libs.

Simply run make in this directory, e.g.:

$ make
cc -std=c11 -Wall -Wextra -g -Iinclude -D_DEFAULT_SOURCE -D_POSIX_C_SOURCE=200809 -I/usr/include/libpng12 -c src/main.c -o build/main.o
cc -std=c11 -Wall -Wextra -g -Iinclude -D_DEFAULT_SOURCE -D_POSIX_C_SOURCE=200809 -I/usr/include/libpng12 -c src/ql.c -o build/ql.o
cc -std=c11 -Wall -Wextra -g -Iinclude -D_DEFAULT_SOURCE -D_POSIX_C_SOURCE=200809 -I/usr/include/libpng12 -c src/loadpng.c -o build/loadpng.o
cc -lpng12 build/main.o build/ql.o build/loadpng.o -o build/qlprint
$

Running

Syntax:
  qlprint [-p lp] -i
          [-p lp] [-m margin] [-a] [-C|-D] [-W width] [-L length] [-Q] [-n num] [-t threshold] png...
Where:
  -p lp         Printer port (default /dev/usb/lp0)
  -i            Print status information only, then exit
  -m margin     Margin (dots)
  -a            Enable auto-cut
  -C            Request continuous-length-tape when printing (error if not)
  -D            Request die-cut-labels when printing (error if not)
  -W width      Request particular width media when printing (error if not)
  -L length     Request particular length media when printing (error if not)
  -Q            Prioritise quality of speed
  -n num        Print num copies
  -t threshold  Threshold for black-vs-white (default 128, i.e. 0-127=black)
  png...        One or more png files to print

The PNG files are converted to monochrome internally. The black-vs-white threshold for this conversion may be tuned with the -t threshold argument.

Image height is limited to the capability of the printer (720 for most, 1296 for 1050/1060N models). Attempting to print larger images will fail.

On successful printing, the exit code is zero; in case of any error, the exit code is non-zero and an error message is printed to stderr.

Examples

Show printer status information

Here with a narrow continuous-length-tape cartridge loaded.

$ ./build/qlprint -i
          Printer: QL-570
             Mode: no-auto-cut
           Errors: none
       Media type: continuous-length-tape
 Media width (mm): 29
$

Printing with auto-cutter enabled:

$ ./build/qlprint -a example.png
example.png (135x135) OK
$

Printing two images, cutting only once

$ ./build/qlprint -a example.png example.png
example.png (135x135) OK
example.png (135x135) OK
$

Printing two copies of the one image, cutting after each

$ ./build/qlprint -a -n 2 example.png
example.png (135x135) OK
example.png (135x135) OK
$

Print only on the correct media type

Assuming a continuous-length-tape cartridge is installed:

$ ./build/qlprint -C example.png
example.png (135x135) OK
$

...otherwise:

$ ./build/qlprint -C example.png
Printer reported error(s): replace-media
$