I have a set of sandpapers that has the following papers:
60 AN
100 GB
120 DN
180 FB
All have the marking S/C/W/P paper T9 C Closed. These are all paper sheets. I know that the number is the grain size.
What do the other markings mean?
Especially the 100 GB. I've noticed that it behaves somewhat different to its grit size compared to the others. I am guessing that the G means its the thickest paper? The backside looks different compared to others.