3D printing, also called additive manufacturing, is a way of making a physical object by adding material in thin layers until the shape is complete, following a digital model. Unlike traditional methods that cut or mold material, it builds only what's needed, which produces less waste and allows complex shapes. It's widely used for prototyping and small-batch parts.

What are the main types of 3D printing?

Three cover most needs: FDM, which melts plastic filament and lays it down through a nozzle (the common desktop type); SLA, which cures liquid resin with light for fine detail; and SLS, which fuses nylon powder with a laser for strong functional parts. They differ in cost, detail, strength, and materials.

What materials can be 3D printed?

Most consumer printing uses thermoplastics like PLA, ABS, and PETG (FDM) or photopolymer resins (SLA). Industrial processes print nylon powder (SLS) and even metals. For a founder, plastic is almost always where you start, because it's cheap and fast for prototyping.

What is 3D printing used for?

Its biggest value for product people is prototyping: it turns a design into something you can hold in hours, so you can test and refine before spending on tooling. It's also used for jigs and fixtures, custom or low-volume parts, replacement parts, and complex geometries that are hard to make any other way.

What Is 3D Printing?

Updated November 13, 2026

3D printing, or additive manufacturing, builds a physical object by adding material one thin layer at a time, following a digital model, instead of cutting it out of a solid block. That simple difference is what makes it fast, cheap for one-offs, and able to produce shapes other methods can't. This guide explains what 3D printing is, the main technologies, the materials, and what it's actually used for.

Additive, not subtractive

3D printing: additive manufacturing: making a physical object by adding material in successive thin layers, each fused to the one below, as directed by a digital model, rather than cutting or molding it.

The whole idea sits in one word: additive. A 3D printer builds only what's needed, layer by layer, from the bottom up. Compare that to subtractive manufacturing like CNC machining, which starts with a block and cuts the part out, or to injection molding, which needs an expensive mold. Because a printer adds material instead, it wastes little, needs no tooling, and can make shapes that would be hard or impossible otherwise.

The three main technologies

Technology	How it builds	Best for
FDM (filament)	Melts plastic filament and lays it down through a heated nozzle	Affordable desktop printing, prototypes, the beginner's choice
SLA (resin)	Cures liquid resin with light, layer by layer	Fine detail and smooth surfaces: miniatures, dental, detailed models
SLS (powder)	Fuses nylon powder with a laser; loose powder supports the part	Strong functional parts and small production runs, no supports needed

FDM is the one most people picture and the right place to start. The step-by-step mechanics of each are in how does 3D printing work.

Materials

Most consumer printing uses thermoplastics: PLA (easy, the beginner default), ABS, and PETG on FDM machines, or photopolymer resins on SLA. Industrial processes add nylon powder (SLS) and even metals. For a founder prototyping a product, cheap plastic is almost always where you start, because it's fast and forgiving.

What it's used for

For product people, 3D printing's biggest payoff is prototyping. It turns a design into something you can hold in hours, so you can model, print, learn, and adjust without spending on tooling. Beyond that, it's used for jigs and fixtures, custom or low-volume parts, replacement parts for things no longer sold, and complex geometries that are awkward to make any other way. It's less suited to high-volume production, where a mold's low per-part cost wins.

Where it fits in making a product

Think of a 3D printer as a prototyping tool before it's a factory. It's the cheapest way to iterate a design until it's right, after which you move to a production process for volume. For the bigger picture of how parts get made, see how products are made, and to go hands-on, start with 3D printing for beginners.

Working on your own product? The idea-to-shelf program is the step-by-step system behind these guides, from idea and prototype through manufacturing and launch.

Frequently asked questions

What is 3D printing?: 3D printing, also called additive manufacturing, is a way of making a physical object by adding material in thin layers until the shape is complete, following a digital model. Unlike traditional methods that cut or mold material, it builds only what's needed, which produces less waste and allows complex shapes. It's widely used for prototyping and small-batch parts.
What are the main types of 3D printing?: Three cover most needs: FDM, which melts plastic filament and lays it down through a nozzle (the common desktop type); SLA, which cures liquid resin with light for fine detail; and SLS, which fuses nylon powder with a laser for strong functional parts. They differ in cost, detail, strength, and materials.
What materials can be 3D printed?: Most consumer printing uses thermoplastics like PLA, ABS, and PETG (FDM) or photopolymer resins (SLA). Industrial processes print nylon powder (SLS) and even metals. For a founder, plastic is almost always where you start, because it's cheap and fast for prototyping.
What is 3D printing used for?: Its biggest value for product people is prototyping: it turns a design into something you can hold in hours, so you can test and refine before spending on tooling. It's also used for jigs and fixtures, custom or low-volume parts, replacement parts, and complex geometries that are hard to make any other way.

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