So, you've probably got a few extra spools lying around. Me too. I use my 3d printer to make lots of miniatures for tabletop gaming, and I like to have those painted. By drilling a few holes, sized appropriately for whichever brand of paint you use, you can make a rack suitable for paints. Smaller holes can be used to accommodate brushes, or an empty paint container with no lid. Additionally, small plastic cups, the kind you use for the bathroom, fit perfectly into the center hole for brush cleaning water. Finally, if you set these up correctly, they stack.
I've included an stl file to give you an idea of what it should look like. I've laid out 1.5 in and .25 in holes for 10 paint containers and 10 brushes. I suppose you could print it, but why wouldn't you just use an old spool instead?