Deep line used by this painter (5)
I believe the answer is:
lowry
'this painter' is the definition.
(LS Lowry, 1887-1976)
'deep line used by' is the wordplay.
'deep' becomes 'low' (similar in meaning).
'line' becomes 'ry' (abbreviation for railway).
'used by' says to put letters next to each other.
'low'+'ry'='LOWRY'
(Other definitions for lowry that I've seen before include "Painter of bleak scenes" , "He painted" , "L. S. -, English artist" , "'English painter, famous for his stick people (5)'" , "L. S. --, English painter" .)