Wilson or Penn? Mystery Cache

Approximately 325 million tennis balls are manufactured annually. They consist of a felt covered rubber ball filled with air. Balls begin losing pressure as soon as a package is opened; for this reason those used in competition are kept under pressure until they are needed. Tennis balls used in competition must meet specific criteria for size, weight, bounce, and deformation. Most tennis balls are a fluorescent "optic yellow" color which enhances visibility. The rubber in tennis balls does not decompose quickly and results in 22,000 tons of waste per year. Many balls never make it to landfills and end up "lost" in parks around the world. A lucky few end up being recycled into tennis court surfaces or given a second life through upcycling. The internet has hundreds of photos of upcycled tennis balls - take a look for yourself.