Want to get more serious about contact juggling? Then you do need to be particular about the balls you're working with. But which balls are best will depend on the type of contact juggling you like to do, in addition to a few other considerations, such as your experience level and whether you plan to be performing.
The basic differences among contact juggling balls are their sizes and construction material. Balls generally run from about 2.5 inches (6.5 centimeters) to 5 inches (13 centimeters) or more and are crafted from hard, scratch-resistant acrylics or a variety of softer materials. Four-inch (10 centimeters), soft-material balls are recommended for beginners working on basic one-ball maneuvers, as they're easier to work with. Professionals also prefer 4-inch balls, although theirs are typically made of acrylic [sources: Ministry of Manipulation, Serious Juggling].
Think you'd like to work on body rolling, like chest rolls and arm rolls? Then you need a stage ball about 5 to 7.5 inches (13-19 centimeters). This makes them easier to roll along your body. Palm-spinners, by contrast, should look for smaller balls, as palms are smaller than arms and legs; 2.5-inch balls work well [source: Serious Juggling].
Plan to be performing? Pros favor vibrantly colored balls for aesthetic purposes. Clear orbs that evoke a crystal ball-like appearance are also popular. Acrylic is their material of choice because of its supreme durability. Of course, if a professional performs some body-rolling moves, he'll likely use a stage ball, which works better and is easier for the audience to see.
Still a bit confused? Then buy a few balls of various sizes and materials. Luckily they're not that pricey; a 2.5-inch palm-spinning ball is less than $20, for example, while a 4-inch acrylic ball is about $35 [source: Serious Juggling].
Whether you end up following in Michael Moschen's footsteps or simply learn to rock the "butterfly," any contact juggling skills you learn will keep you and others entertained for the rest of your life.