What's a Fabric Burn Test?A fabric burn test can help you discover if a fabric is 100% cotton or made from other fibers. A  fabric is tested by setting a small piece on fire and monitoring the results.Knowing fabric content is important for quilters who swap fabrics with others, since we usually sew with all-cotton fabrics, and for anyone else who wants to be sure of proper care instructions for any project.You Might Say... 'But I Always Buy All-Cotton Fabrics'Do you ever buy fabrics on eBay or at estate sales and flea markets? What about your non-quilting friends, do they ever offer to give you excess fabrics? Have you received fabrics in a swap that you're not sure about?Unless you are sure that fabrics are cotton, there's no way of knowing their fiber content without performing a few tests.Fabric Burn Test SuppliesThe fabric(s) you want to test.A flameproof container with walls -- try a large ashtray and consider placing it in another container, such as a sink where water is handy.Long matches or another source of a small flame.A pitcher of water to extinguish the flame if you aren't working in a sink.Long tweezers or a hemostat.Do the Burn TestPerform the burn test outside on a day that's not windy, or in a well-ventilated area inside, away from flammable items, children, and pets. Testing in a flameproof container placed in a stainless steel sink is one option.