Other forms: swatches
A swatch is a small piece of fabric that's used as a sample. If you're considering buying a purple velvet couch, you can order a swatch to see if it's really going to match your living room rug.
A swatch is useful because it gives you an idea of what something larger—like curtains, a dress, or an upholstered piece of furniture—will look like. Sometimes swatch is also used for samples of other things, like paint colors or makeup. Swatch comes from 16th-century Scots, in which it was used to mean "a tally fixed to a piece of cloth before dyeing."