Self-Adhesive Write & Seal Calibration Labels printed green on high quality, non-rip matt white permanent vinyl with a gloss clear write and seal tab to provide additional print protection by sealing the label from water and cleaning solvents etc. Suitable for both internal & external use, our write and seal calibration labels measure 40x25mm & are supplied in packs of 100. Calibration Labels can be written on with most pens. For best adhesion apply to flat, clean and smooth surface.