Atropos

Yep! I am a mechanical engineer and manual machinist.

My experience with my own self hosting has led to my current added responsibility as IT for our 6 person startup. But 90% of my time is mechanical engineering.

I guess this may indeed be a z issue, those diagonal lines could be when the nozzle moved from corner to corner without laying material down.

I don’t think this has anything to do with the material or temperature or anything like that.

I’m not overly familiar with the Ender, but maybe run a bed levelling protocol or other calibration option? The plate is probably toast unfortunately.

What printer? Is this a residue that is raised, or a depression on the plate, or just a surface finish reflectivity change?