Vertical banding appears only in black & white documents, not color. Likely cause: The iPL algorithm for monochrome masking has desynced. Fix: Run a "Bi-D Adjustment" via the Maintenance Manager (requires service mode).
For the average user, it looks like a typo or a forgotten driver file. But for technicians and power users, understanding the iPL engine is the key to diagnosing banding, speed throttling, and unexpected shutdowns. epson mfp-ipl
Disclaimer: This post is for educational purposes regarding legacy hardware. Epson no longer actively supports the iPL architecture in new consumer products. Vertical banding appears only in black & white
Workaround: Use the generic "Epson ESC/P-R" driver. It bypasses the proprietary iPL logic entirely, though you will lose ink level monitoring and maintenance tab features. For the average user, it looks like a
Unlike simple host-based drivers that rely on your PC’s CPU to do the heavy lifting, the iPL subsystem processes raster data inside the MFP. This was Epson’s proprietary solution to offload work from the computer back in the early 2010s.