Summary
Press together Paint Rack for miniature paints. This was designed for Vallejo dropper bottles, but the holes have plenty of clearance for anything close. Citadel paint pots will not fit.
Files are for a K40 using K40 Whisperer. I've included the dxf, svg, and a Fusion 360 export.
Make sure to use 3mm wood, as the slot size is sized for that. For assembly I also added some wood glue as the fit was not very tight.