I’m working on a Project that Prominently Features a Red PETG Top Surface that after the Printing is done gets Sanded with Grits from 400-2000 +Heat Treatment.

There is a Big Issue tho, After the Sanding is done, I can Rather Prominently see the Walls and Infill of the Layers Below. At first I suspected that I just sanded too much and that the internals weren’t really filled in 100% as they should, but after some testing and Closer Inspection, it just seems the Red PETG is just Transparent enough that I can see the layer below…

So how do I stop this from Happening? Thus Far I played around with Fan Speeds, Nozzle Temps (±10°C), Layer Hight and Ironing all Solid Layers with Mixed Success, non Satisfactory enough however…