PLA (Polylactic Acid)
Created from plant products, such as corn, potatoes, sugar beets, etc., PLA is considered a more "earth-friendly" material than other petroleum-based plastics like ABS. PLA can be composted at commercial compost facilities. It won't bio-degrade in your backyard or home compost pile, however.
PLA is an excellent material for beginners, as it's easy to print with due to the fact that it has minimal warping tendencies. It can even be printed without a heated bed if needed. PLA is fairly strong but more brittle than ABS, and it has a semi-gloss finish. PLA's lower melting temperature makes it a poor choice for objects that require significant heat resistance. For example, PLA objects left in a hot car may become deformed.
ABS (Acrylonitrile Butadiene Styrene)
ABS is a petroleum-based plastic. It is stronger, with slightly more flexibility compared to PLA. It also offers improved heat resistance, making it suitable for engineering purposes or items with mechanical properties.
ABS can be more challenging to print with, due to its tendency to warp, especially where the object makes contact with the build plate. Applying a coating of "ABS juice" (a mixture of ABS and acetone) on a glass build plate can help greatly to reduce warping. While printing, ABS produces a smell of hot plastic, so proper ventilation is important.
While printing, ABS produces a smell of hot plastic, so proper ventilation is important.
ABS dissolves in acetone, so you can use a few drops of acetone to weld ABS parts together. You can also use acetone vapor to post-process ABS parts, creating a smooth, glossy finish.
Nylon
Used by many manufacturers worldwide, Nylon (polyamide) is well-known for its impressive durability, high strength-to-weight ratio, flexibility, low friction, and corrosion resistance. Nylon is fairly flexible when thin, but also very strong. With its ability to withstand significant mechanical stress, Nylon is a great choice for 3D printing tools, living hinges, functional prototypes, and end-use parts.
Nylon is very sensitive to moisture absorption, so it is important to store nylon filament in a dry place with desiccant. If there is water uptake, you may need to take additional precautions to dry the filament before use.