The Thornhill jacket is made using a medium grey brushed cotton. Essentially the fibres have been lifted and treated to leave the surface smooth and velvet-like to the touch. This same procedure allows the cotton a very slight sheen and stops the cloth from absorbing light and appearing flat.
This Thornhill jacket is a double-breasted military style biker jacket but using an uncommon brushed cotton. There is are pleated panels on the sides at the back to allow extra movement and come practically from allowing a rider to comfortably have their arms raised for longer periods. This was a common trait in sporting jackets and can be seen largely in vintage garments across hunting, skiing and motorcycling.