I am attaching two files tcpdftest.pdf and tcpdftest.zip. The PDF is the file generated with the test/proof of bug.
This file looks good on the screen on any device (Windows, Mac, iOS looks fine), but on 50% of the printers the pdf will produce nothing but tiny squares where the text should be.
Turning on or off font subsetting makes no difference.
Turning on or off PDF unicode makes no difference.
Experimenting with different encodings in TCPDF_FONTS::addTTFfont makes no difference.
Some additional details on the printers tested
Samsung C460FW: Works
Canon MF8380Cdw: broken
HP P1102: broken
HP M551n: Works
Please tell me if there is anything unclear or if there are additional test cases or anything else where I can help.
Is there anything I can do to improve the test case attached above?