Models work well for team building, client engagement and fostering design enthusiasm. Many of these models are made to explain concepts, look at options and predict form and light early in the process. Several models have solid acrylic pieces that look glass-like, etched with a knife or laser and sanded for translucence. Some site models use magnet sheet pieces attached below buildings so they can be moved around metal bases for maximum flexibility and design engagement. Mechanical torch cutting and a newer technique borne out of recent sculpture is using MIG welding for assembly and texture.