Cosmetic produced backchat and criticism (8)
I believe the answer is:
lipstick
'cosmetic' is the definition.
(I know that lipstick is a type of make-up)
'backchat and criticism' is the wordplay.
'backchat' becomes 'lip' (I've seen this in other clues).
'and' means one lot of letters go next to another.
'criticism' becomes 'stick' (as in giving someone stick).
'lip'+'stick'='LIPSTICK'
'produced' acts as a link.
(Other definitions for lipstick that I've seen before include "girl may have to face" , "Colour applied to the mouth" , "Cosmetic used to colour around the mouth" , "Type of cosmetic" , "Pick list, oddly, for the cosmetic" .)