This design is set up to be compatible with future models I will be releasing. Alternatively, you can create your own models that interface with these using the attached dimensional drawing for the connector pieces. Printing is simple, no supports necessary, and should be done with about 40% infill. The hermetic ( airtight ) seal is afforded by a silicone foam cord that is press fit into a groove along the rim of the case. The cord is 4mm diameter, and was purchased here, but any supplier is fine. https://www.ebay.com/itm/165035895399?chn=ps&mkevt=1&mkcid=28&var=464579457199

The cord should be cut to length AFTER it has been fully pressed into the groove, with a small amount of extra length so that the ends press firmly together once pressed into the groove.

There are two versions, one with large disposable wells intended for painters that use large volumes of paint, and one that is better suited to miniature painters with trays with smaller wells and sponges for humidity. The sponges used here are regular scotchbrite sponges that have been cut into strips (3 x 0.6in x ~16mm).