Just lovely. It seems that a couple of big name stores were mislabeling some of their textile products. If you happened to buy something labeled as bamboo from Walmart or Kohls in the last 10 years or so, you might want to check if it’s actually bamboo or not.
And how, pray tell, you ask might one discern without a microscope and your very own Abby Sciuto? You do a burn test. I first heard about these when we played in the Society for Creative Anachronism (SCA). In the SCA, you try to make your costumes/garb as close to period as possible. Some folks take this more seriously than others. But generally, if you can use natural fiber cloth, the look is much more believable, whether you used a sewing machine or sewed by hand.
Medieval clothing can take up a lot of yardage, so to save money, it’s not unusual to buy up unmarked bolts or household linens at thrift shops. But to double-check the fiber content, people can ask for a swatch, take it outside and burn that sucker. Natural vs. synthetic is an easy determination. The natural fiber will smell of hair (woolens) or burning paper. Synthetics smell acrid and frequently melt.
So, yes, you can figure out if that garment or tablecloth is actually bamboo. You’re going to need to snip off a piece from a discrete area of the garment and burn it in a safe place. What you do from there, is entirely up to you.