Files with the .BTW extension contain packs of data forming a product label with its barcode. The packs can contain barcodes, formatted text, images, and graphical elements, as well as their layout.

BTW files are saved using the professional software called Bartender, made by Seagull Scientific specifically for the creation of label projects and barcodes. It contains saved ready-made elements of barcodes and special markings to help during the creation. It can also be used for coding RFID -which stands for Radio Frequency Identification – markers.