This 1995 Honda Accord was still performing well when it came to us in 2019. But the paint looked like hell! The paint had develop a problem called microchecking. Over time microchecking leads to paint failure and rusting. It is characterized by small cracks (or "checks") in the paint. They look like lots of small razor cuts and are usually the result of temperature extremes. So it is common to first see the problem over the car's radiator where the paint experiences the most extremes of heating and cooling. The cracks allow water to get under the paint so metal body parts start rusting.
This post provides a very nice photo progression of the car going through sanding and masking processes in the shop.
Before:
During Sanding:
Masking Process:
After:
Before:
After:
Before:
During Sanding:
Masking Process: