I've studied industrial design for a few years, here is what I can tell you: Plastics is a very large subject and there are a lot of criteria that can be invol

I've studied industrial design for a few years, here is what I can tell you: Plastics is a very large subject and there are a lot of criteria that can be involved. You criteria apparantly are: - Can be made in small series. (ie. no injection molding or extrusion) - Holds electrical circuitry. - Serves mainly the purpose of container. (no exceptional stresses, no special features, must be able to open and close in some way.) - Consumer product, so must have somewhat nice finish. - Should be tappable for screws? - Production accuracy within 1-2 millimeters? - Can be made in your own workshop? Here are some small-series techniques you could look into: - (Resin) casting - Dip molding/casting - Heat molding - Spin casting - Vacuum forming - Hand laminating or spraying I don't know what materials are exactly applicable to what technique, but for your purpose some common materials are: PP, PS, Styrene-butadiene, ABS (especially), PA6, Polyester (resin). Goodluck!