Prusaslicer: Any way to get Ironing on a single layer high (0.2mm) part?
Hi, Im building an LED light bar, and for that I've decided to make a diffusor out of white PETG. Here it is so you can see what im talking about. Its a single layer of PETG, surrounded by black PETG to shield each LED from light bleed of the neighbouring LEDs.
The white PETG works super well for diffusing, but since a layer isnt perfect its still possible to see some dark and bright spots in the Diffuser. Using two layers (0.4mm) doesnt really mitigate the dark spots, but using Ironing genuinely gives me a perfect result.
The problem with using two diffusion layers (0.4mm) is that the loss in brightness is pretty high compared to a single layer, so I would prefer to use a single layer and enable ironing for that. The brightness loss doesnt really show up in the picture and I've had to add green plexiglass to get my phone to even expose the details correctly.
But it seems like its impossible to use ironing on a 0.2mm high plane? Here is a cube squashed to 0.2mm total height in prusaslicer, with ironing enabled:
Now, the same cube but with 0.4mm total height:
As you can see ironing works. But I cant find any way to get prusaslicer to iron the first layer.
Im open to all suggestions, hacks, etc. Is ther some way to do this?
Posted Feb 28, 2026, 1:11 PM UTC