What is crosslinking finish, drak? I have never heard of that term before.
The thing is,i know it isnt scratches from previous grits, because i always start with 2000 grit.
It is almost like a little grain of sand or something gets under the sandpaper while i am wet sanding, no matter how clean i keep the paper.
And if i do it by hand, with the same grit, there are still areas that the 2000 paper seemed to scratch more harshly than others.