Wikipedia
Tolex is a trade name for a flexible, water-proof, vinyl material used as a cover material for books, upholstery, guitar amplifiers, cases, and other products. It has been used in Henney-Packard hearses and ambulances of the 50's and Fender amplifiers, and guitar cases from various manufacturers.
Tolex was filed as a trademark on August 30, 1945 by the General Tire, and is currently registered as "a plastic sheet and film material for book binding and case covering for speakers and amplifiers." Tolex was also used in Packard automobiles, hearses, and ambulances—and in marine applications, such as Chris-Craft boats and other watercraft.
Musicians sometimes use "Tolex" as a generic description for any vinyl type covering on an amplifier or guitar case—but most are not actually Tolex brand, except for Fender and Rickenbacker related products.