What PSI should I run my wide belts at? 
The recommended PSI for our wide belts is as follows: 45 – 55 PSI for paper
55 – 65 PSI for regular cotton cloth
65 – 75 PSI for polyester
You will occasionally see poly belts being used to plane or dimension metals or wood with a PSI over 70. For these types of operations, this is acceptable. Paper belts should never be used for these types of applications.