This is the basis for my storage rack, its a sewing thread rack I rescued from a thrift store. It fits both the apple barrel craft type paints and the shorter model round paints for painting model cars and things like that. The thread spools are meant to slip over the pegs, I slide paint bottles between the pegs.
Step 1: Paint Bottles About This Size.
These are the types of paints I'm talking about, the one ounce type, half dollar coin around. I spray paint the lids white and paint a bit on the lid so I can see the color on the outside.
Step 2: Fixing the Pegs
The spacing is slightly too large , the bottle will slip through. The solution is to stick some type of sleeve over the pegs.
Step 3: Ta-Dah!
I used leftover Aquarium tubing. You could also anything else around the size. Like a bit of 1/8 inch rubber line from the auto parts store. If you are going to use taller craft paint bottles like the green one above, cut the tubing about 3/4 inch longer than the pegs, it will keep the bottles from tipping out of the rack.