The Amundsen Flannels is one beefy, indigo-dyed heavy shirt. Even thicker than UES' extra heavy flannel, these yarns are rope-dyed indigo and densely woven giving the shirt a sturdy drape. Amundsen fabric features an unusual weave satin material that was developed in the Bishu (Aichi Prefecture) in Japan during the time the namesake explorer was traveling through Antarctica. Rough and firm, the interior has been brushed for a softer hand. Due to the rope-dyed indigo fabric staining the machines, very few factories can support the weaving of this fabric. Woven on vintage power looms, production is slow yet results in a strong and well made garment.