Modular Paint Rack

I originally set out to simply make a smaller version so I could print it on my small printer however as I was adding slots and tabs to reassemble I noticed by modifying a bit more I was able to make it more versatile. I don't have corner designs however this design can be expanded either vertically or horizontally. For my own I started expanding vertically and then as you can see in one of my pictures I started expanding horizontally.

capacity is any multiple of 6 with each column holding 3