I designed a NeoNail nailpolish organizer for my wife. I designed the bottom of the box to have slots so the individual Nailpolish flasks wouldnt be able to tilt. The slots themselves have a diameter of 25mm so any nailpolish with that diameter should fit. There is a 3x3 and 4x4 slot version, personally I would recommend the 4x4 ones.
The box itself is designed to be stackable.
The lid is just the bottom part of the box sliced off. :)
Dimensions:
Slotdiameter: 25mm
Hight: 80mm
Width and lenght: 116mm