I tend to use Lowes or Home Depot 0.187" Chalkboard MDF as prototype material. Cuts easily on my PRU. It comes in either 2’ x 3’ or 2’ x 4’ depending on whether I get it at Lowes or Home Depot. It is just MDF that has a black coating on one side so that it can be used as a chalkboard. A little more pricey than straight MDF at $9.95 a sheet but still an available bargain. The nice part is that the black side doesn’t suffer from smoke damage since it can be wiped off. Mask the other side if you care about it. With the right settings it doesn’t char much but still creates a lot of smoke residue. They also carry a version called Whiteboard.
Draftboard might be a better choice for those that have a week to wait for each delivery.
I’ve since cut this a few more times (I have a lot of paints) using the maple plywood, and it came out great. I’ve also added zip tie holes to the back so that it can be fastened down to something behind it. Finally, I’ve also added a second rack type for the one sitting on top of a stack that has a shelf for other supplies.
Yeah, I’ll just release it on Thingiverse. How many paint droppers wide by tall are you looking for?
As a side note, I don’t have any army painter droppers, so I can’t confirm ahead of time that they fit (thought I hear they are basically the same size as vallejo)