High tack adhesive is a pressure-sensitive adhesive with a high initial tack (stickiness) and high ultimate adhesion. Tack is the property of materials that allows them to adhere to a surface immediately upon contact. Polyester Chemical Labels are supplied with a 1.8 mil thick, high tack adhesive that sticks well to a wide range of surfaces immediately on contact, and this is twice as thick as other adhesives. The high-tack adhesive creates an immediate solid bond between a label and a substrate that strengthens into a strong permanent bond that will not allow the label to be removed.