Out of the blue my SG400 printer has started putting strange marks that cover the entire surface of my prints when using a light shade of grey. The image below is a close-up of a portion of a PU leather sublimated mousepad and as you can see the surface is covered with speckly white lines.
I have not changed any of my printer (SG400) or paper (A-Sub)/pressing settings, and other prints using different colours/shades seem to be printing out perfectly. I've tried three head cleans and even a head flush to no avail.
Image link: https://i.imgur.com/Ql4OM9N.jpg