Gestetner CS210 Color Manual page 88

Guide to Components
Master film position sheet
Make a copy of the master sheet onto type C film
and use the copy to position the film correctly on the
exposure glass.
Make a copy from the original sheet, cut around the
surrounding margin on the dotted lines, and cut away
the center part corresponding to the size of the film
to be copied.
Keep the master film position sheet.
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