This is a remixed version of aggyface's excellent design.
- I've added tabs to position the levels placed on top of each other, even though I think it's best to glue them together.
- Added holes so the bottles can go in tip first for upside down storage. To accommodate this, print at least the bottommost with the longer legs (PaintRackStable.stl). If you don't glue them, then all of them should be that variant.
They can be printed without supports.
Edit: I've added 30mm versions, but I have not printed those yet.