The idea of printing an object

Chuck Hull patented stereolithography — building a solid object layer by layer, curing liquid resin with a laser — in 1986, and founded 3D Systems to commercialize it. For its first two decades, 3D printing was strictly an industrial tool: expensive machines used for rapid prototyping, out of reach for anyone outside a company or lab.

Going open source

The RepRap project, started by Dr. Adrian Bowyer around 2005, had a specific goal: build a 3D printer that could print most of its own parts, designed to be open source and cheap to replicate. Around the same time, key early patents on FDM (fused deposition modeling — melting and extruding plastic filament, the most common consumer method) began expiring, clearing the way for companies like MakerBot to sell affordable desktop printers built on that open, shared foundation. That combination — expired patents plus an open-source hobbyist community — is why 3D printing became a consumer hobby starting around 2009.

How the common types work

  • FDM (fused deposition modeling) — melts plastic filament and extrudes it layer by layer. Cheapest and most common; visible layer lines; good for functional parts.
  • Resin (SLA/MSLA) — cures liquid resin with light, layer by layer. Much finer detail than FDM; messier and smellier to work with; better for miniatures and detailed models.

Beyond printers: CNC and laser cutters

3D printing is "additive" — building up material. Its counterpart is "subtractive" manufacturing: a CNC (computer numerical control) mill or router cuts material away from a solid block, and a laser cutter burns or cuts through flat material. Many hobbyists end up with some combination of all three, since each is better suited to different materials and jobs.

Industrial use today

Beyond hobbyists, additive manufacturing is now a real part of aerospace (lightweight metal parts), medical devices (custom implants, dental work), and rapid prototyping in product design — anywhere a company needs a complex part fast, or shaped in a way traditional manufacturing can't easily produce.