The NextDent 5100 Printer comes with one resin tray per machine purchased. Purchasing multiple resin trays gives the user the ability to easily print with two different materials on one machine. The more resin trays you have, the more materials you can print with. If the resin tray is sufficiently cleaned in between builds, it is also possible to use a different print material in the same resin tray. However, not every resin can share the same tray, even if the resin tray is cleaned.