This red shirt, made by Pendleton, is 100% wool.
The shirt was seen on Vinted: https://www.vinted.co.uk/items/6825369510-authentic-macpherson-red-tartan-pendleton-check-plaid-lodge-shirt-wool-shacket-vintage-medium. Photo credit Swallowed a Fly. Seller’s description: ‘Authentic Macpherson Red Tartan Pendleton Check plaid lodge shirt thick wool shacket vintage Made in USA American medium Excellent condition. The label dates this shirt between 1970 and 1994. Pit to pit 22” Pit to cuff 21” Shoulders 18” Length 33”’.
Threads of Belonging 