Pla is a biodegradable thermoplastic that has been derived from renewable resources like corn starch and sugar cane this makes pla environmentally friendly and very safe to work with pla also has a very sharp glass transition point so if you use a fan to cool it it will set into a solid very quickly pla can achieve a greater range of geometries than are possible with other plastics it also reduces the thermal stress on the printed part making warping less of an issue with larger pla par