MATTRESS MAKER is a job title for someone who manufactures mattresses. Two of the most well-known mattress makers are Serta and Sealy, both of which have been in business for over a century. Serta was founded in 1931 and is now one of the largest mattress manufacturers in the world. Sealy was founded in 1881 and is known for its innovative designs and technologies. Both companies produce a wide range of mattresses, from traditional innerspring to memory foam and hybrid models.