Complex sentence: A skilled mimeo operator using an electrostencil and a very coarse halftone screen could make acceptable printed copies of a photograph, although this took considerable care both in preparing the stencil and in maintaining evenness of ink flow during printing.
Split into simpler sentences: A skilled mimeo operator using an electrostencil and a very coarse halftone screen could make acceptable printed copies of a photograph. This took considerable care both in preparing the stencil and in maintaining evenness of the ink flow during printing.