Many sets use cotton/polyester blends (commonly 55% cotton / 45% polyester). Some tops are 100% cotton, while several pajama pants are 100% polyester or microfleece.
Men's sizes often span S to XXXL, women's flannel sets typically come in S–3X (covering smaller through plus sizes), and children’s/family options include youth sizes such as 8Y.
Most pajama pants feature pull-on elastic waists; many also include adjustable drawstrings and some listings offer a button fly for extra adjustability.
Women's flannel sets are generally described as loose-fitting and are sold across a broad size range that includes smaller sizes through plus sizes (for example S–3X).
Common top styles include thermal henleys with three buttons, button-front flannel shirts with notch collars, and long-sleeve round-neck tops.
Common patterns include red-and-black buffalo (lumberjack) plaid and classic black-and-white plaid. Some men’s sets offer camo, and seasonal/holiday designs may feature motifs like a truck with a Christmas tree or 'Merry Christmas' lettering.