Dyes can start to thin, smothered in salts (9)
I believe the answer is:
tinctures
'dyes' is the definition.
The answer and definition can be both substances as well as being plural nouns.
Perhaps there's an association between them I don't understand?
'can start to thin smothered in salts' is the wordplay.
'can' becomes 'tin' (both are metal containers).
'start to' suggests taking the first letters.
'smothered in' means one lot of letters goes inside another (I've seen this in other clues).
'salts' becomes 'cures' (I've seen this in another clue).
The first letter of 'thin' is 't'.
't' placed inside 'cures' is 'ctures'.
'tin'+'ctures'='TINCTURES'
Can you help me to learn more?