0.4MM nozzle,
PLA of any type or brand, including standard and matte, official and non official bambu PLA.
I’ve tried printing from 200-220, ramping my cooling fan up to 100% for the final layer, slowing the top layers down to 50 mm/s using ironing, tightening the hot end screws, flow rate calibration, many different types of pla, on any big, flat print like signs etc I get these melty lines on the top layer.
Bed temp is 45 with a supertack plate. It doesn’t seem to be an issue on prints without a big, top flat layer.
Also doesn’t happen with petg as far as I can tell, only PLA.
on many prints it seems fine at the edges of where it starts laying down a specific color, and this only occurs as it goes towards the inside
edit: i’ve discovered it seems to be a layer deposited on top, rather than anything pushing up from below i.e pillowing. I can scrape it off and have a seemingly perfect looking top layer underneath…