We recommend using 30252 labels on the DYMO 450.  However, we also support using 30334 and 30321 labels.



Update 12/01/14:  Additional label sizes are now supported via DYMO Direct Printing.  While in SETTINGS > LIST when you select your printer from the drop-down list, as shown in the video below, you can also choose the label size you want to use (30252, 30334, 30336 or 30321) from the second drop-down.