This is a tray to hold 15 dropper paint bottles (such as Vallejo or Army Painter brand paints). Three trays will fit into an ArtBin 12" Deep Base Carrying
...Plus Case (link below) for a total of 45 bottles per case.
This was inspired by https://www.thingiverse.com/thing:2024692 but I wanted the ability to work with some paints without having a large tray in my work area. I landed on having three smaller trays instead of 1 large one. While not as an elegant design as theirs, this will allow you to lift a tray out to work with up to 15 paints per tray.
https://www.amazon.com/ArtBin-12-Inch-Carrying-Container-6977AB/dp/B001ELDERU/
