Avery White TrueBlock Technology Inkjet Shipping Label 3-1/3" x 4" Box Of 600, create professional-looking labels quickly with Shipping Labels with TrueBlock Technology. Labels with TrueBlock completely cover everything underneath so you can reuse mailing tubes, boxes and more. Bright white labels have permanent adhesive and are jam-free and smudge-free. Perfect for creating professional-looking mailings, shipping, bar coding and organizing. Labels are designed for use in inkjet printers. Avery offers many easy-to-use templates for Microsoft Word and other popular software programs.