Plasticizer is a type of chemical additive that is used to improve the flexibility and stretchability of paper. Plasticizers are substances added to the paper pulp during the manufacturing process to modify the physical properties of the paper.

The primary function of a plasticizer in papermaking is to increase the elasticity and reduce the brittleness of the paper. This is particularly important for certain paper products, such as those used in packaging or labeling, where flexibility is a desirable characteristic.

Common plasticizers used in papermaking include certain types of resins or chemicals that can modify the cellulose fibers in the paper, making them more pliable. However, the choice of plasticizer depends on the specific properties desired for the end product and the intended application of the paper.