It holds paint droppers like Vallejo paints come in. It stacks and has holes for wall mounting, they are 3mm.

I designed this from scratch in F360, but I used an existing model from thingiverse as my idea and it is essentially a copy of that with some minor tweeks so I will call that out  [https://www.thingiverse.com/thing:3362084](https://www.thingiverse.com/thing:3362084) is what inspired me.

I was originally just going to modify an STL so I could wall mount it, but then I just designed it on my own for fun so I could also add a shelf model and potentially other types of holders.  Mine takes longer to print and is not really any better, but I thought I would share it.

The shelf is flat and level I may add other parts to this if I come up with additional things I want.

I glued mine together, but you do not have to, it is sturdy on a desk just stacks or if screwed into a wall.