Mario sleepwear uses cotton and polyester-based fabrics. Examples from the product descriptions include 100% cotton for some kids' sets; polyester–spandex blends such as 92% polyester / 8% spandex; and polyester with small spandex amounts (95% polyester / 5% spandex).
Most Mario sleepwear items are machine washable and can be tumble dried. Specific notes include washing inside out in cold water and tumble drying low for some men's pieces, and washing inside out with like colors and tumble drying on low for certain kids' items.
Mario pajama pants most commonly use pull-on elastic waistbands. Many men's styles add an adjustable drawstring and a functional button fly. Some kids' pants list full waistband elastic or a 1-inch elastic waistband and feature cuffed legs for a secure fit.
Mario sleepwear features bold, all-over character prints and repeating themed patterns—examples include porthole-style repeats, full-coverage repeating graphics on pants, and prominent character artwork on tops.
Descriptions list fabrics such as knit for some kids' sets and microplush for multiple pajama pants, along with polyester–spandex blends noted for a smooth, stretchy feel.
Men's Mario pajama pants are described as having a relaxed or regular fit. The polyester–spandex fabrics are soft and stretchy, offering flexibility and lightweight breathability for lounging or sleeping.