I need it to do a print in silent mode without opening the openprinterdialog On Mac. On Windows works well, but not on Mac.
you can print a file with a shell
shell.execute "lpr " + file.ShellPath
I tried this:
lpr -P Brother_QL_570 image.png
Exits in the print queue, but does not print.
image.png - this will not be the right path
drop the file image.png to a terminal window and you see the shellpath