QTR-Quadtone RIP

I was printing a b+w image onto the Epson Premium Glossy paper using
QTR.  I was testing the image lightness/darkness on 4x6 paper, and I
only had glossy.

I had one problem as the image printed well, with neutral greys and
rich blacks.  My problem was:

The image scratched easily.  I have never seen this before with the
Epson paper.  Is this because the profile is  for matte?  Would the
same problem occur with luster paper?

Does anyone have any thoughts on this?

Jeff