A while ago my work bought a tape library with a barcode reader. By that time, we were making heavy use of AMANDA for our backups, and we needed to keep the physical tape labels in sync with AMANDA's tape labels as stored on disk. Unfortunately, the preprinted labels that came with the drive weren't very good. We looked into getting custom-made replacement ones, but they were so expensive we wondered if they were made of platinum.
Thankfully, the barcodes used by our library (code 39) are well-known, so I set out to make a Postscript program to produce custom labels. This is the result. It was meant to be used with a Sun StorEdge L8 autoloader, which is a Quantum OEM unit. I'm sure barcode readers in other tape libraries will be able to grok these patterns, though.
The file is a Postscript program which includes a trivial barcode encoder for Code 39, and enough logic to make columns of tape labels on demand.
You can open it in your favourite text editor and customise the colours and set the tape labels you want printed. The default file prints prefix letters in yellow and numbers in orange. It includes six cleaning tapes (CLNxxx), six diagnostic labels (DIAGxx), and six backup tapes.
The labels don't need to be printed on adhesive label stock. Simply fold the flap along the label's long edge and insert in the DLT cartridge label slot. The shape of the folded label will keep it in the slot, even in a fast tape library (which, in case you're wondering, the L8 was not).
An example sheet of DLT barcodes showing colour-coding. The standard allows six letters or digits and we can fit 18 labels per sheet. The top half of each label is folded behind it to make the label lock in the label slot, so adhesives aren't required.
Generate Labels on the Web
If you don't want to get your hands dirty, you can use my DLT label generator which will make any labels you like. It's free! (but not converted to this new page yet!)
AMANDA and No Tape Library?
If you use AMANDA and don't have a tape library, you might also be interested in my custom Postscript inlay for DLT cartridges for DLT cartridge cases.