A few FDM-ready building corners I made to go with the 28mm sci fi greebles models I uploaded earlier. This will look great with just a little bit of drybrush. Designed to slot 4mm foamcore board. There's a 2mm offset between the slots, so when you calculate the wall size, take 2mm off each side, you'll figure it out.
I'm currently designing a version for SLA printers with more detail.
Might need to print with brim or on a heated print bed