What is the difference between calendered and non-calendered trampoline mats?
Calendered and non-calendered trampoline mats both start with similar cross-woven polypropelene fibers. To make it calendered, the mat is then run through a series of large, heated rollers, which to some degree melt and flatten the fibers, so that they are fused together at the intersections of the weave pattern. One of the effects of this is that the mat has a much smoother feel. Another is that the fibers have less of a tendency to shift, causing them to either squeeze together or open up into holes in different areas. A non-calendered mat will probably give the user more traction and have less of a tendency to slip while performing maneuvers, but there is opportunity for mild injury due to abrasion (think skinned knees). By far, the majority of manufacturers chose to go with calendered fabric, probably just because it feels nicer in bare feet. In general, calendered fabric is more expensive because of the extra manufacturing step.
