Leather industry
The most important when you need to decide which sammying felt to use is to know how many pressure cylinders has your sammying machine. Sammying machines are built with 2, 3, 5 or more pressure cylinders and the consecutive stress for the felt is very different from one to the others.
Type of hides, type of felts used up to now, type of tanning, or any problem which occured can help in the sammying felt recommendation.