There are not actually that many types of 3D printing. Despite the proliferation of brand names and marketing terminology, every 3D printer on Earth falls into one of seven technology families. Once you understand those families, you can read any printer spec sheet and know exactly what you are looking at.
This guide walks through each of the seven 3D printing technology families, what they are best at, what they are not, and how to pick between them.
1. Material Extrusion — FDM / FFF
The most common 3D printing technology, found in everything from $200 desktop printers to industrial machines running 24/7. A thermoplastic filament is unspooled, heated, and extruded through a nozzle that moves in X and Y while the build plate moves in Z.
Pros — Cheapest per part. Huge material catalog. Simple, reliable, serviceable. Good for large parts. Handles engineering thermoplastics (PETG, ASA, PC CF).
Cons — Layer lines are visible without post-processing. Anisotropic (weaker across Z). Overhangs need support.
Best for — Functional prototypes, jigs and fixtures, cost-sensitive builds, large parts.
2. Vat Photopolymerization — SLA / DLP / LCD
A vat of liquid photopolymer resin is cured layer by layer by a UV light source. SLA uses a laser to trace each layer. DLP uses a projector to flash an entire layer at once. LCD (also called MSLA) uses an LCD screen to mask a UV array.
Pros — Smoothest surface finish. Tightest dimensional tolerances. Fine feature resolution. Clear and flexible materials.
Cons — Parts are more brittle than thermoplastics. Post-processing (washing, curing) is required. Resin is more expensive than filament.
Best for — Visual prototypes, jewelry patterns, dental models, snap-fit validation.
3. Powder Bed Fusion — SLS / MJF / DMLS
A thin layer of powder is spread across a build plate and selectively fused — by laser (SLS, DMLS, SLM) or by inkjet fusing agent plus heat (MJF). Unfused powder supports the part as it builds, eliminating the need for printed supports.
Pros — Production-grade mechanical properties. Isotropic strength. No supports needed (free undercuts). Batch consistency.
Cons — Expensive machines. Rough as-built surface. Longer overall turnaround because of cool-down time.
Best for — Production nylon parts (SLS, MJF), metal production parts (DMLS).
4. Material Jetting — PolyJet / VCJ
Inkjet heads deposit droplets of photopolymer that are cured in place by UV light. Different heads can deposit different materials in the same build, enabling full-color and multi-material parts.
Pros — Full color. Multi-material in a single build. Smooth as-built surfaces.
Cons — Parts are brittle. Resin is expensive. Printers are expensive.
Best for — Anatomical models, photorealistic prototypes, multi-material assemblies.
5. Binder Jetting
A binder agent is selectively deposited onto a powder bed, creating a "green part" that is later sintered or infiltrated to reach final properties. Used for sand casting molds, metal parts, and ceramics.
Pros — Very fast compared to powder bed fusion. No heat during printing (binder is cured at low temperature). Scales well to high volume.
Cons — Green parts are fragile. Sintering and shrinkage require design compensation. Not as widely available as other processes.
Best for — Metal production parts at volume, sand casting molds, ceramic prototypes.
6. Directed Energy Deposition — DED
Metal powder or wire is fed into a focused energy source (laser or electron beam) that melts it onto an existing surface. Used primarily for repair of high-value metal parts (turbine blades, molds) and large-scale metal deposition.
Pros — Can repair existing parts. Handles very large metal builds. High deposition rate.
Cons — Rough as-built surface — always requires machining finish. Expensive and specialized.
Best for — Metal part repair, large-scale metal builds, cladding.
7. Sheet Lamination — LOM / UAM
Sheets of material (paper, metal foil, plastic film) are stacked and bonded, then cut layer by layer to form the final part. Ultrasonic Additive Manufacturing (UAM) uses metal foils bonded with ultrasonic vibration.
Pros — Fast. Cheap materials. Multi-color (paper version).
Cons — Rarely used commercially. Limited material properties. Part quality is lower than other processes.
Best for — Concept models, niche metal composite parts.
How to read a 3D printer spec sheet
Once you know the seven families, you can classify any printer by asking three questions:
- What is the feedstock? Filament, resin, powder, or sheet.
- How is it joined? Melting, photopolymerization, fusing, gluing.
- What is the build envelope? This tells you the maximum part size.
Which family is right for your project?
- Cost-sensitive prototypes: FDM
- Visually accurate prototypes: SLA
- Production nylon parts: MJF (or SLS if you need specialty materials)
- Metal parts: DMLS through a specialized partner
- Full-color models: Material Jetting (VCJ)
- Very large parts: FGF (industrial FDM) or Industrial SLA
- High-volume metal production: Binder Jetting
