This diamond-shaped pattern is named for a clan whose tartan it was patterned after
... a design 
consisting of a pattern of varicolored diamonds on a solid background (originally 
for knitted articles); patterned after the tartan of a clan in ... Diamond-shaped 
pattern [DOC] [TLE] Argyle (pattern) - Wikipedia [PAR] An argyle (occasionally argyll) pattern is made of diamonds or lozenges.