Bull Denim
What does Bull Denim mean?
Via 3×1 twill construction, bull denim is a heavy and tightly knit denim weave greater than 14 Oz..
Heddels explains Bull Denim
Constructed of coarse, often slubby yarns with a 3×1 twill weave, bull denim are often greater than 14 Oz. and used for other garment besides denim jeans.
Additional Resources
Washed pigment dyed bull denim hat
Source: uniformclothing.net