Satisfied returning a touch of paint with time – this paint? (7)
I believe the answer is:
tempera
'this paint?' is the definition.
(tempera is a kind of paint)
'satisfied returning a touch of paint with time' is the wordplay.
'satisfied' becomes 'met' ('meet' can be a synonym of 'satisfy').
'returning' is a reversal indicator.
'a touch of' suggests taking the first letters.
'with' says to put letters next to each other.
'time' becomes 'era' (I've seen this before**).
The initial letter of 'paint' is 'p'.
'met' in reverse letter order is 'tem'.
'tem'+'p'+'era'='TEMPERA'
(Other definitions for tempera that I've seen before include "decorative style" , "A paint and a painting technique" , "Artist's emulsion" , "Paint made using egg-yolk" , "Painting method using emulsion" .)