The skin wasn't firm, you say (5)
I believe the answer is:
suede
'the skin' is the definition.
(suede is a kind of skin)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for suede that I've seen before include "Hide from kids" , "Type of leather" , "Fabric" , "unprepared material" , "Form of leather" .)