Even though stair tread rugs are tiny pieces of carpet compared to other rug styles, they do require a pad underneath for cushion support. Be mindful when choosing the padding, however, as anything too thick will peak out from the bottom of the stair tread, creating an unsightly appearance.
Be sure to choose a dense option so the stair tread rug stays securely in place. A general rule when choosing an underpad is to go 1/4-inch-thick and keep it narrower than the size of your stair tread rug. Rubber is a good material, as it offers firm support.
Now that you know what materials and styles are out there, you can decide on any special features and narrow down the right size of your stair tread rugs. Remember, for underfoot comfort, go for wool and be sure any patterned designs you choose are displayed on a straight staircase to get the most from this style.