A 3D printer needs two basic inputs to produce an object: a digital file that tells it what to build, and a physical material to build it from. The specific material depends on the type of printer, but most home users work with plastic filament, a spool of thermoplastic wire that melts and is deposited layer by layer. Beyond these essentials, there are consumables and accessories that keep prints sticking, the nozzle functioning, and the results looking sharp.
The Digital File: From 3D Model to Printer Instructions
Your printer can’t read a 3D model directly. You start with a design file, typically in STL, OBJ, or 3MF format. These files are mathematical representations of shapes with no instructions your printer can actually use. They define the geometry but say nothing about how to build it.
That’s where slicer software comes in. Programs like Cura, PrusaSlicer, or BambuStudio take your 3D model and convert it into G-code, the programming language your printer understands. G-code is a long list of commands telling the printer exactly where to move the nozzle, how fast, how hot to heat the material, and when to extrude. The slicer is where you choose settings like layer height, print speed, and infill density. The G-code file is then loaded onto the printer via USB drive, SD card, or Wi-Fi.
Plastic Filament: The Most Common Material
Most consumer 3D printers use fused deposition modeling (FDM), which feeds a spool of plastic filament through a heated nozzle. The filament melts, gets deposited in thin lines, and cools into a solid object. Standard filament comes in 1.75 mm diameter spools, though some printers use 2.85 mm.
The three most popular filaments are PLA, ABS, and PETG, each with different properties and temperature requirements:
- PLA (polylactic acid) is the easiest to print with and the most popular for beginners. It’s rigid, strong, biodegradable, and nearly odorless. It prints at 190–220°C and doesn’t require a heated bed, though one helps. The tradeoff is that it’s brittle and doesn’t hold up well to heat or chemicals.
- ABS (acrylonitrile butadiene styrene) is tougher and more heat-resistant, making it better for functional parts. It prints at 220–250°C and requires both a heated bed and good ventilation because it releases fumes during printing.
- PETG (polyethylene terephthalate glycol) sits between the two. It’s humidity and chemical resistant, somewhat flexible, and highly transparent. It prints at 230–250°C and can be food safe in certain formulations. It’s a solid choice for waterproof parts and snap-fit components.
Beyond these three, nylon prints at 240–270°C and is valued for its toughness, while TPU (a flexible filament) prints at 210–230°C and produces rubbery, bendable parts. Polycarbonate is the strongest common filament but demands nozzle temperatures of 260–310°C and a printer built to handle that heat.
Specialty and Composite Filaments
Composite filaments mix a base plastic (usually PLA or PETG) with particles of another material. Carbon fiber-filled filament contains short carbon fibers that dramatically increase stiffness and reduce weight. Wood-filled filaments blend fine wood particles into PLA, giving prints a textured, organic look that can be sanded and stained. Metal-filled filaments use powdered copper, bronze, or steel to create parts with a metallic appearance and surprising heft. Glow-in-the-dark filaments contain phosphorescent particles.
One important catch: the particles in composite filaments are abrasive. They will chew through a standard brass nozzle in weeks. If you plan to print with carbon fiber, metal-filled, or glow-in-the-dark materials, you’ll need a hardened steel nozzle (typically 0.6 mm) or a ruby-tipped nozzle, which pairs a brass body with a synthetic ruby gemstone for both heat conductivity and extreme wear resistance.
Resin for High-Detail Printers
Resin printers (SLA and MSLA) don’t use filament at all. Instead, they use a liquid photosensitive resin that cures into solid plastic when exposed to UV light. You pour the resin into a shallow tank, and the printer selectively hardens it one ultra-thin layer at a time.
Resin produces parts with far more detail than filament printers, making it popular for miniatures, jewelry, and dental models. Standard resin creates rigid, detailed parts. Tough resin mimics the impact resistance of ABS. Rubber-like resin is soft to the touch with high flexibility, suited for parts that will be bent or compressed. Castable resin burns out cleanly, so jewelers use it to create molds for metal casting.
Resin prints require post-processing that filament prints don’t. You’ll need isopropyl alcohol (or a specialized wash solution) to clean uncured resin off the part, and a UV curing station to fully harden it. These supplies are part of the ongoing cost of resin printing.
Powder for Industrial Printers
Industrial 3D printers often use powder-based processes. A thin layer of powder is spread across a build platform, and either a laser or electron beam selectively fuses it. Common polymer powders include nylon (PA 12), which produces tough, functional parts. Metal powders include stainless steel, titanium, aluminum, cobalt chrome, and copper. These machines cost tens of thousands of dollars and are mostly found in aerospace, medical, and manufacturing settings, not home workshops.
Bed Adhesion Supplies
Getting the first layer to stick to the print bed is one of the most common challenges in 3D printing, and a whole category of supplies exists to solve it. The build surface itself matters: options include PEI sheets (the most popular on modern printers), glass plates, Kapton tape, Buildtak sheets, and textured steel plates.
When the surface alone isn’t enough, adhesion aids help. Glue sticks (standard school glue sticks work fine) are the most common solution. Hairspray is another popular choice, particularly formulations containing vinyl neodecanoate copolymer as an active ingredient. Some users apply a thin layer of painter’s tape to glass beds. These are cheap, consumable supplies you’ll restock occasionally.
Nozzles and Replacement Parts
The nozzle is the component that melts and deposits filament, and it wears out over time. Standard brass nozzles are inexpensive and offer excellent heat transfer, making them ideal for PLA, ABS, and PETG. They typically come in 0.4 mm diameter, which balances detail and print speed. Smaller nozzles (0.2–0.3 mm) produce finer detail but print much slower. Larger nozzles (0.6–0.8 mm) sacrifice detail for speed.
For abrasive filaments like carbon fiber composites or metal-filled plastics, hardened steel nozzles resist wear but conduct heat less efficiently. Ruby-tipped nozzles are the premium option, maintaining a precise opening even after thousands of print hours with abrasive materials. If you’re printing anything that will contact food, a stainless steel nozzle is the safe choice, since standard brass nozzles can contain lead.
A Note on Safety: Fumes and Particles
3D printers release ultrafine particles and volatile organic compounds when melting plastic. ABS is the biggest concern, emitting roughly 200 times more ultrafine particles per minute than PLA pellets. ABS also releases styrene and ethylbenzene during printing. PLA is much cleaner but still releases small amounts of benzene and toluene. The majority of particles released are ultrafine, in the 1–100 nanometer range, small enough to penetrate deep into your lungs.
Printing in a well-ventilated room is the minimum precaution. An enclosed printer with a HEPA filter or carbon filter is better, especially for ABS, nylon, or polycarbonate. Many experienced users keep their printers in a garage, spare room, or purpose-built enclosure rather than in a living space or bedroom.
Food Safety Considerations
PETG and PLA are often marketed as food safe, but the reality is more complicated. FDA food safety standards require a smooth, nonabsorbent, easily cleanable surface with no migration of harmful substances. 3D printed objects are inherently porous, with tiny gaps between layers that trap bacteria and resist cleaning. Even if the raw filament is technically food safe, the printing process introduces variables: the nozzle material, colorants in the filament, and the microscopic surface texture all matter.
If you want to use a 3D printed object with food, the safest approach is to coat the finished part with a food-grade epoxy or polyurethane to seal the surface. Use a stainless steel nozzle rather than brass, and choose a filament that’s specifically certified as food grade, with no composite particles or questionable additives.