This is a modular wall rack for Vallejo (or similar sized) hobby paints to be organized on the wall with the bottom of the bottle facing out so that it's easier to find the color you need.
There are size grid sizes available (if you would like a specific grid dimension, just ask and I can create a new size). If you need to store a large amount of paint, I suggest tiling these prints together and screwing them onto something else first (like ¼" plywood) before mounting on the wall.
Each bottle “slot” has a countersunk hole that accepts a #8 screw for attaching to the wall.
I've supplied a 1x1 that is useful for test printing to ensure fit and so you can check the screw size.
The author hasn't provided the model origin yet.