Just throwing my two cents in for any stray novice scale maker that might read this. Lexan would be a durable choice though it is a brand name. Some plastics suppliers refer to the material as polycarbonate or polycarb for short. By no stretch of the imagination should anyone use the typical acrylic plexiglass. Acrylic cracks and breaks very easily. Now polycarb on the other hand is used to make safety glasses, shatterproof windows, and headlight lenses. Tough stuff to say the least. The only downside it that it only comes in one color, clear.