The researchers first needed to figure out which types of plastic best fit their needs. After melting a number of plastic food utensils under heat lamps and testing their chemical makeup, the researchers found that polystyrene worked best for folding, and the polymer P(3HB) was desirable because it is biodegradable. Then they figured out a way to engineer E. coli bacteria to create the enzymes and proteins needed to make sheets of the plastic. With the plastic in hand, they tried out two different ways to fold it. First, they drew dark lines on the plastic, which, when the plastic was put under infrared light, the dark lines absorbed heat more readily and thus melted that area more quickly. They also put spores of a type of bacteria called Bacillus specifically on the parts they wanted to fold. Bacillus spores expand and contract in different humidity levels, and bend the plastic in the process.