A traditional computer printer involves the user inputting a digital file into software, which then generates a series of instructions and transmits them to a machine (the printer), which interprets them to create a physical copy of that file. 3D printing is similar to that, except that the end product is a three-dimensional object.

The basis of a printed 3D object is a model created using computer-assisted design software (“CAD” for short). It contains numerical data describing the object’s width, height, depth, and overall shape. To prepare it for printing, another program divides the model up into thin layers or “slices” before sending it to the 3D printer. The printer then uses heated plastic filament to draw a two-dimensional shape onto a gradually descending surface, building it layer upon layer into the final product.

The 3D printers at Glencoe Public Library exclusively use Polylactic Acid plastic filament, otherwise known as PLA. Derived from corn starch, tapioca root, or sugarcane, this polyester is a popular material in 3D printing due to its safety and ease of use. PLA can be recycled and will biodegrade under certain conditions, which makes it useful for rapid prototyping and outdoor applications (such as agriculture). When heated, as in 3D printing, PLA emits a mild, inoffensive, syrupy aroma.