It might help you to look up https://en.wikipedia.org/wiki/Mimeograph and possibly other copying techniques. More approachable examples include CD / DVD https://en.wikipedia.org/wiki/Compact_disc_manufacturing or earlier vinyl record production methods.

For the case of chip lithography they'd probably make source masks, copy the first generation a time or two, and use those secondary source masks to produce consumable 'stamps' for production.

Hopefully the stamps maintain sufficient quality across at least a couple batches (50-100+?) of wafers.