Eliminate trips to the Post Office. Print USPS-approved postage directly from you DYMO LabelWriter. White background helps text stand out. Clear, crisp text is far easier to read. Use with DYMO LabelWriter 400 Turbo, Twin Turbo, Duo, 450 Turbo, Twin Turbo, and Duo label printers. Print First Class, Priority, Express flat rate envelope, International Mail (1 oz.) and postcards.