Two of Dick Tremayne's Sweaters

The sweaters Dick Tremayne wears in episodes 26 (2.019, Variations and Relations) and 18 (2.011, Masked Ball) are wonderful examples of his sense of style.

The cardigan Dick wears in episode 26 appears to have been made by Jhane Barnes Menswear. The sweater seems to be a blend of wool, Raylon, cotton, and Lycra. 

Photo Source

The blue, white and black striped cardigan Dick wears in episode 18, while accompanying Andy and Little Nicky for chocolate malteds, appears to be from Etchings. 

Photo source.