With light on, looks silky (5)

I believe the answer is:

rayon

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'looks silky' is the definition.
I can't judge whether this defines the answer.

'with light on' is the wordplay.
'with' means one lot of letters go next to another.
'light' becomes 'ray' (ray is a kind of light).
'ray'+'on' is 'RAYON'.

Can you help me to learn more?

(Other definitions for rayon that I've seen before include "Cellulose fabric" , "Artificial material" , "Artificial silk fabric" , "No ray (anag)" , "Viscose fibre" .)

I've seen this clue in the Evening Standard.

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