American comic's original lines - slick but not edgy material (7)
I believe the answer is:
acrylic
'material' is the definition.
(acrylic is a kind of material)
'american comic's original lines slick but not edgy' is the wordplay.
I cannot quite understand how this works, but
'american' could be 'a' (common abbreviation - e.g. in organisation names) and 'a' is found within the answer.
'lines' could be 'ry' (abbreviation for railway) and 'ry' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for acrylic that I've seen before include "Type of twenty Dn" , "Type of paint or textile fibre" , "Shiny paint" , "Synthetic resin or fibre used for textiles" , "Type of hard paint" .)