Paintballs were originally designed to assist farmers in tagging cattle for identification and have since become a popular recreational activity throughout the country and the world. The balls themselves, which were first constructed from glass, are now actually constructed of food materials: a gelatin shell, food coloring and a few other edible compounds.
The gelatin is mixed in large vats with a sweetener and food dye to give the shell its own color independent of the paint filling. When the gelatin is well mixed, it is poured into long sheets called gelatin strips, which are fed into machines that will puncture circular holes in them to form the exterior of the paintballs.
The paint is made of polyethylene glycol colored with food coloring and thickened to the appropriate viscosity with wax. The paint is mixed separately from the shells, but is then fed into the same machine for the combination process.
The combination machine punctures round holes in the gelatin sheet, which it shapes into semi-spheres. Each of these becomes one half of one paintball shell. The two halves are filled with paint and then fused together. The balls coming out of the machine are then dried and tumbled to ensure proper shaping during the drying process.