Sadly I spoilt an artist’s materials (3,6)
I believe the answer is:
oil paints
'artist's materials' is the definition.
The definition and answer can be both man-made objects as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
'sadly i spoilt an' is the wordplay.
'sadly' is an anagram indicator.
'i'+'spoilt'+'an'='ispoiltan'
'ispoiltan' anagrammed gives 'OIL PAINTS'.
Can you help me to learn more?
(Other definitions for oil paints that I've seen before include "Artist's pigments" , "Painter's media" , "Artist materials" , "What some artists use" .)