Unfortunately the author of that blog didn't realize that the Scots plaiding given to so many slaves and indentured servants was not what we think of as tartan, but rather twill woven cloth from Scottish weavers. It was most often un dyed and was wool an occasionaly linen.

Not understanding the terms used for cloth in the period, it is a common problem with people who have not spent a great deal of time studying the cloth of the period. Hint; Osninburg was not cotton cloth, but linen from the low countries, Bearskin is not the skin of a bear, nor is spotted swanskin something that you took off the Ugly Duckling before having him for dinner..... So you have the misunderstanding we have here today.