LabelKeep is a Mac app that runs (currently) on OSX 10.6, and the Dymo LabelWriter 450 only.  It's easy to install, you download it from our add ons page here, and install it in your applications folder.  Once that's done, you ask us to turn on LabelKeep for your account, and then go into your inventory and click on an item.  Labelkeep should pop up, and give you options for number of labels, and label size.

LabelKeep prints to 3 types of label, all available on our hardware site.