CorningWare, TooLoud and Fringe are companies found on Amazon.com that make oversized coffee mugs. Jumbo mugs can be found on the Zazzle website and oversized coffee mugs are sold on cafepress.com.
CorningWare makes a white 20-ounce mug that comes with a vented plastic cover, which is sold on Amazon.com, as of 2015. This site also sells extra-large 16-ounce mugs made by Fringe, as well as Celtic-style 16-ounce mugs made by TooLoud.
The jumbo mugs found on zazzle.com are 20-ounce mugs and come in a variety of designs. These mugs can be customized with photos, a name or a monogram. The designs for non-customizable mugs range from pictures and paintings, such as Vincent Van Gogh's "Starry Night," to various quotes and phrases. Some of these mug designs are more serious, while many of the sayings and styles are meant to be humorous.
The oversized coffee mugs found on cafepress.com are 15 ounces and also have a wide range of designs and styles. There are simple designs such as black and white plaid, and there are more humours designs with pictures and phrases. This site also sells 16-ounce oversized travel coffee mugs that feature top handles to make them easy to carry.