Lexmark T520 User's Guide - Page 48

14 Tray linking Tray linking enables the automatic linking feature for trays when you use the same size and type of print material in multiple paper sources (trays). For example, let's say you have loaded two optional trays with the same size print material and both are set to the same paper type. When one tray becomes empty, the printer automatically selects print material from the other tray since the printer sees the trays as linked. If you use different print material in the trays, each source with a different print material must have the Paper Type set to a unique value to disable the automatic linking feature. If all the trays do not have the same paper type when they are linked, you could mistakenly print a job on the wrong paper type. 46