One's kid supplies supple leather (7)
I believe the answer is:
doeskin
'supple leather' is the definition.
'doeskin' can be an answer for 'leather' (doeskin is a kind of leather). I'm unsure of the 'supple' bit.
'one's kid supplies' is the wordplay.
'supplies' is an anagram indicator (I've seen 'supply' mean this (in a supple way)).
'ones'+'kid'='oneskid'
'oneskid' anagrammed gives 'DOESKIN'.
Can you help me to learn more?
(Other definitions for doeskin that I've seen before include "glove material" , "Leather from deer" , "Type of leather" .)