Gum is a running gag in Calvin and Hobbes. Calvin enjoys reading Chewing Magazine, and elevates gum chewing to the status of a sport. Gum was mostly featured in later strips that followed the introduction of Chewing.
Calvin is a regular reader of Chewing Magazine, a publication for gum hobbyists which Calvin claims to be a "high-gloss, literate and sophisticated" magazine. However, Hobbes realizes it is an extremely commercialized publication, whose content aims only to increase profits for sponsors. As such, Hobbes expresses overall disgust for the magazine, much in the same way as he disagrees with Calvin about his Chocolate Frosted Sugar Bombs.
- Special issues, such as one on the choice of available sugarless gum.
- Reviews of gum-chewing apparel, such as a perspiration-proof jersey covered in brand logos and fashion knee pads for ambulatory chewing.
- An article advising one to "warm up" before chewing. These warmups prevent the incurring of injuries due to neglect of stretching the temporalis muscles.
- Articles detailing how to set up a "mandibular fitness regime". With this interval training regime, one can build muscle strength and tenacity for better chewing.
- Articles on tongue exercises to blow bigger bubbles.
- Reader surveys. Calvin falsifies his answers to mislead pollsters.
- At least one quiz. The ten-question "Does Your Gum Deliver?" quiz allowed the reader to determine if his brand of gum was giving him "all that he was entitled to".
- An article that compares the top five brands of chewing gum based on flavor retention, elasticity, bubble capacity, and chewing rebound. It was accompanied by a computer graph which demonstrated compensation for various saliva acidities and allowed the reader to select the best gum for his style.
- Updates on available gum flavors.
- An interview with Bazooka Joe.
- Scores of manipulative advertisements.
When Hobbes exclaimed shock for the existence of a gum chewing magazine, Calvin replied that there must be a dozen such publications, each geared to a different class of gum chewers. Calvin named two of them: "Gum Action", which he said "aimed for the gonzo chewers", and "Chewers Illustrated", which he claimed was targeted at collectors of vintage gum.