The difference between fabrics

I have two Latigo strops. Both are 3 inch leather strops from SRD. The first one I bought with the back strop being matched webbing, the second one I bought with the back strop being premium fabric. Both front strops are leather with the backs being some kind of fine almost sand paper material. I also bought the chromium oxide spray. I watched a YouTube video and it showed that spray being used on the back strop. My questions are
1. What is the difference between the mesh, and the premium fabric
2. What is the back of the leather strop(the sand paper material) used for and when and how do I use it?
3. Should I ever use the back of the leather strop(the sand paper material) for refreshing the blade?

Thanks

The difference is they are made of different materials-really. Most would say they work the same whether fabric or the webbing type. Historically nice thick knobby linen is the premium material with canvas probably second. You see very few true Linen strops being made today but there are a few.

I don't know about the finish you have on the backs of your strops. None of mine have that.

It sounds like the back of the leather is just the rough flesh side. I would never put a razor on that rough of a surface. Potentially you could strip the surface down and get it to be like a nice suede but it would take a bit of effort. I have a paddle for use with paste, it keeps my hanging strop clean that way. It's a personal preference. You could paste one side of your fabric. Be sure to clean your razor before going from paste to your clean strop surfaces otherwise everything is eventually a pasted strop

I'm with Shaun and would only use the back of the fabric or webbing. Personally I also prefer to keep pastes away from my daily strop to avoid contamination. Once contaminated that is it.