Early mattresses contained a variety of natural materials including straw, feathers or horse hair. In the first half of the 20th century, a typical mattress sold in North America had an innerspring core and cotton batting or fiberfill. Modern mattresses usually contain either an inner spring core or materials such as latex, viscoelastic or other flexible polyurethane foams. Other fill components include insulator pads over the coils that prevent the bed's upholstery layers from cupping down into the innerspring, as well as polyester fiberfill in the bed's top upholstery layers. Mattresses may also be filled with air or water, or a variety of natural fibers, such as in futons. In Southeast Asia, bedding is made with kapok. In 1900 English-born engineer, James Marshall introduced the first individually wrapped pocketed spring coil mattress now commonly known as marshall coils and founded Marshall Mattress, a company that bears his name and is still in operation in Toronto, Canada. He allowed VI-Spring patent rights in England where they were known as Marshall Mattress of England until the 1930s.