I believe I successfully argue that check shirts are a defining article of Southeastern fashion, which developed in the mid-1750's. In short, check linen shirts grew in popularity. While seen only on occaision in 1754, by 1758 they were the most common shirt material seen in the SE. White linen shirts were the most common in 1754 and quickly took the back seat by '58.
We have plenty of references to shirts being adourned with silver buckles (ring broaches) and being worn until they are nearly rotting off of the owner's body. Adair tells us Indian men wore their shirts until they were filthy. Another author states the shirts were so filthy that they were nearly black. This is likely the story for both white linen and checked linen shirts... they got filthy.
But there is a shirt decorating technique which does not appear to have been practiced in the Southeast, and was apparently a Northeastern style: painting the shoulders red. There are a number of references to the shoulders of white shirts being painted with vermillion. We could speculate all day long about why it was done. But it certainly was done in the Northeast.
Painting the shoulders of a trade shirt red seems to not have been in fashion in the SE. To my knowledge, there is not a single reference to Indian shirts with red painted shoulders in the South. This is very likely just another way that Northeastern and Southeastern peoples could tell each other apart. I would highly suggest that until such time as we can produce evidence for the practice, that interpreters of Southeastern cultures avoid the application of red pigment to the shoulders of their shirts... let them get dirty naturally. It won't take too long!
Up next will either be a full blown post about the lack of quilled items in the Southeastern or a rant against bad metallic ornaments like gorget style nose rings, brass armbands, ear wheels, elaborate pattern broaches... BS trade guns with 42" barrels... or all the above. ;)