#763 Epson L120 (escp2-l120): text doubled sideways at Standard and High quality

[Ilyua]

Printer: Epson L120 over USB. Gutenprint 5.3.5, CUPS 2.4.19, cups-filters 2.0.1, Ghostscript 10.07.1, NixOS

Text prints with a horizontal ghost. Each vertical stroke appears twice, side by side. The amount depends on the quality setting:

• Standard (361x360dpi): strong doubling
• High: slight doubling
• Best: clean

What I tried with the same PDF page:

• StpPrintingDirection=Unidirectional: still doubled at Standard
• StpFullBleed=True and False: no difference
• LibreOffice and Evince: both doubled, the filter chain is the same
• escputil -a -m escp2-l120: the test page shows 7 squares, not pairs of lines with numbers, so I could not align the head this way

Epson's own Linux driver (epson-inkjet-printer-201310w 1.0.1) prints the same page on the same printer clean and much faster at its Standard quality. So the printer mechanics and the nozzles seem fine. The printer's nozzle check is clean too

I did not find the cause in the driver. I can run test patterns or send more data if this helps