Cross-linking describes the reaction of the dispensing material and is also re-ferred to as hardening or curing.

The cross-linking of polymers can either take place via functions that already exist in the polymer or through the addition of a cross-linking agent (hardener). The consistency is altered through the cross-linking process. The most common procedures are curing using heat, UV light, moisture, oxygen (aerobic hardening) or simply through a chemical bond with a second component (hardener).