Which is better, photocopying or printing?

An offset (printing) plate with a coating on its surface can produce a planar workpiece with ink transfer area and non-ink transfer area on it, and the two areas are in the same plane.

Photocopying: use genuine copy, the paper quality may be worse. Generally speaking, there is no discrepancy between the originals, but there are several missing pages and dislocations.

So it is better to use offset books.