An adaptive brush holder for your crafting space. With no scaling, this suits 25 small/med brushes but can be scaled up just a bit to hold larger items. NO SUPPORTS REQUIRED.

You can print this with a hole in the bottom (i.e. use a negative volume additive feature in PrusaSlicer) to give you a gap into which you can pour plaster or cement to give this some heft - thus I recommend 5% gyroid infill, as this will allow the cement to distribute inside the shell.

I'm giving this brush holder a generous CC-attrib-share alike license, so feel free to make it, change it, improve it, sell it …. whatever you like. Go nuts ;)