Cloaking stripped artwork with clay (6)

I believe the answer is:

kaolin

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

I don't understand how the rest of the clue works.

(Other definitions for kaolin that I've seen before include "China clay" , "Soft white clay, used for making fine porcelain, say" , "Nil oak in the ceramic clay" .)

I've seen this clue in The Hindu.

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