3D Printer Resin is a liquid photopolymer used in resin-based 3D printing methods like SLA and MSLA. It hardens when exposed to specific wavelengths of light (usually UV), allowing printers to build highly detailed models layer by layer. After printing, parts come out coated in uncured “wet” resin, which must be cleaned to remove excess material. This is typically done by rinsing the print in isopropyl alcohol (IPA) in a wash station, until the surface is free of sticky residue. Once cleaned, the part is dried and then placed under UV light in a curing station (or sunlight) to fully harden and reach its final strength. Proper gloves and ventilation are important throughout, since uncured resin can be irritating and hazardous to skin.