Years ago I ripped the old rusted out duct work from my hallway and thought it would be cool to use the holes that left above the doorways as some sort of stylized window / ventilation path, now that I have my MPCNC I finally have something up there! I started making Fallout themed lithophanes, this one out of 1/8" HDPE.
A vacuum table would have been very useful for this, but getting my hands covered in rice grain looking plastic chips manually holding down the center part that wanted to pop up wasn’t too bad. The HDPE machined really well with the usual 1/8" flat endmill and the occasional squirt of water to keep it cool. I may have given myself cancer by breathing it in but it looks cool so it’s worth it.