Scratch

Manifests as: fine-line surface damage
Primarily caused by: small sharp points or edges

There are various types of scratches that affect prints in different ways. Some scratches are discrete furrows in the surface of the print from which material has been removed. Others are basically cuts through the print surface. Finally, there are also shallow micro-scratches, which do not impact the printing colorants but can affect the gloss of the print. Scratches tend to be more objectionable with images than text unless they are so wide that they obliterate letters making the document difficult to read.

Scratch is completely different from abrasion.  Scratch is damage caused by a small point dragged across the surface of a print, such as a finger nail, while abrasion is damage caused by the motion of a broad surface over a large area of a print (such as when a print is inserted into or removed from a paper storage envelope).  Because of these differences, abrasion is treated as a separate deterioration manifestation. 

Below is an example of a deep furrow down the center of a digital print. Both the colorant and the image receiving layer were removed when a sharp object was dragged across the surface of the print.

A gouge down the center of the print where colorant has been removed
A gouge down the center of the print where colorant has been removed

In the image below, the surface layer has been cut by a sharp point. The image layer has pulled back at the cut edges revealing the white paper underneath.

Multiple scratches to print surface
Multiple scratches to print surface

Digital print materials as well as traditional photographic materials can be quite susceptible to scratch. The surface of some digital prints is so fragile that scratching can be caused by objects that would generally seem harmless. For example, in the print below, the surface was scratched by the corner of another print.

Scratches caused by corner of another print
Scratches caused by corner of another print

Finally, in some digital photographic prints the colorants reside inside a clear binder such as gelatin or polyvinyl alcohol. This clear binder protects the colorants against damage, but rough surfaces can still mar the binder causing scratches or a loss in gloss. This is hard to see except in low angle light.

Low angle light reveals scratches
Low Angle Light Reveals Scratches

Direct Illumination Hides Scratches
Direct Illumination Hides Scratches