Crossword Genius

Plain concept is revolutionary, used regularly as template (7)

Ross

I believe the answer is:

stencil

'template' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for stencil that I've seen before include "Clients for copying device" , "Method of decorating" , "Text template" , "It's perforated for ink or paint to pass through" , "Cut-out for painting patterns or shapes" .)

I've seen this clue in The Times.
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