A better description would be dimpled similar to a golf ball. I'm not sure if it will show up but here is an example. You can really see it in the darker areas. I think what is happening is that the spherical shape of the dimple is reflecting the light from the scanner as the head goes by.
Get a very clean sheet of glass, soak the prints in a water and PhotoFlo (Calgon, etc.) solution and scan while wet, then plaster the print side to the glass and let dry. That's how they get the glossy finish on old gelatin-paper (not this new-fangled resin-coated stuff) prints, although they sometimes used enameled metal plates or glossy stainless steel. Clean and spotless is the important part.






