The most common and most likely answer to this crossword clue is the 7 letter word STENCIL
I've seen this crossword clue in The Daily Telegraph
S
T
E
N
C
I
L
More clues leading to the result STENCIL
- Plain concept is revolutionary, used regularly as template
- Design aid: tool for drawing street for page
- Insect ruined large sheet full of holes
- Design aid — tool that draws street for page
- Artist’s guide confused clients
- Model held up in acrylic net stockings
- Template for drawing nicest wavy line
- Outline device to have a lasting impression?
- Means of creating letters, say, clients reproduced
- Copy perplexed clients
Buddy explains!

The straight part
We know that "copy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case copy = stencil.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does STENCIL mean?
STENCIL noun- A thin sheet, either perforated or using some other technique, with which a pattern may be produced upon a surface.
- A utensil that contains a perforated sheet through which ink can be forced to create a printed pattern on a surface.
- A two-ply master sheet for use with a mimeograph.
- To print with a stencil.