The filament of the 3D printer allows the fused deposition modeling 3D printers to work. This kind of 3D printer works by melting the filament through a heated nozzle and extruding it to build up something three-dimensional, layer by layer. Filaments come in different diameters but are usually 1.75 mm or 2.85 mm; they are also available in different materials, colors, and properties and, hence, intended applications and finishes.

Several types of 3D filament used in the industry have different properties for various applications. Polylactic acid is outright known to be the most popular based on its ease of use and biodegradability. Acrylonitrile Butadiene Styrene, on the other hand, is well known for its strength and durability, providing great sections for functional parts. PETG combines the easy-printability properties of PLA and the strength of ABS, is great in layer adhesion, has good chemical resistance, and is a blend. TPU refers to thermoplastic polyurethane, which is a type of thermoplastic elastomer. This is a flexible filament; hence, it is excellent for parts that have the properties of rubber. Other specialty filaments include Nylon, though not as strong, Polycarbonate, is very strong, with composite materials infused with carbon fiber, wood, or metal particles.

The best filament for 3D printing, however, really depends on the purpose of your project. For general use in printing and ease of use, PLA seems to be recommended since it has a low printing temperature and minimal warping. ABS or PETG is indicated more if there is a need for more durability, and for resistance to higher temperatures. If flexibility in parts is desired, then TPU would be a better choice. Thus, the choice of the best filament is governed by factors such as mechanical properties, heat performance, and intended use of the printed object.

Beginners in 3D printing usually find that PLA filament is a good starting material because of its low melting temperature and minor warping, making it more convenient to work with compared to other materials. It also means that PLA can adhere well to the print bed without needing a heated bed or enclosure, which in turn makes printing easier. Biodegradable, this material is available in a wide range of colors, making it quite viable for newcomers to 3D printing.

The proper storing of 3D printing filament might be of prime importance in the maintenance of quality and performances proposed for the printing product. Filament should be stored in a dry place to avoid moisture absorption, which could cause problems with printing like bubbling and poor layer adhesion. Storing in airtight containers with silica desiccant sachets is recommended. Some save them in vacuum-sealed bags for long-term storage. Also, storing the filament away from direct sunlight and extreme temperatures helps preserve its properties to a large extent. Other ways to ensure quality printing at all times are by checking for filament for moisture, such as when the filament is brittle or has surface defects.