In this guide · Part 1 of 7
Key takeaways
- 3D printing, also called additive manufacturing, builds objects layer by layer from a digital file.
- Every print follows the same workflow: get a 3D model, slice it, print it, then finish it.
- The two most popular types for home, school and business use are filament (FDM) printers and resin printers.
- Filament printers are the most versatile all-rounders. Resin printers produce the finest detail.
- You don't need 3D design skills to start, because huge numbers of ready-made models are available to download.
What is 3D printing?
3D printing, also known as additive manufacturing, is the process of making a three-dimensional object from a digital design by adding material one layer at a time. Most traditional manufacturing works the other way round. It either cuts, drills or machines material away from a solid block (subtractive manufacturing), or injects material into a mould.
Because a 3D printer only puts material where it's needed, it can make shapes that would be difficult, slow or expensive to produce any other way. These include hollow parts, internal channels, interlocking pieces and one-off custom designs. There's no mould or tooling to pay for, so a single item costs roughly the same per part as a batch of ten.
Each layer is very thin, typically between a few hundredths and a few tenths of a millimetre. Hundreds or thousands of layers stacked together make the finished part.
How does a 3D printer work?
Whichever type of 3D printer you use, every print follows the same simple workflow.
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Get a 3D model
A 3D model is a digital file that describes the shape of an object. You can download ready-made models from online model libraries (many are free), scan a real object with a 3D scanner, or design your own in 3D design (CAD) software. The most common file formats are STL and 3MF.
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Slice the model
Slicer software cuts the model into hundreds or thousands of horizontal layers and works out exactly how the printer should build each one. It adds supports where needed and lets you choose settings such as layer height and strength. The result is a print file the printer can read.
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Print it
Send the print file to your printer by Wi-Fi, an app, USB or a memory card. The printer then builds the object layer by layer. A print can take anywhere from a few minutes to more than a day, depending on its size and settings.
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Finish it
Remove the print and tidy it up. That might mean snipping off supports, sanding or painting, or for resin prints, washing and curing.
What are the main types of 3D printer?
There are many 3D printing technologies, but two of them account for the vast majority of printers used at home, in schools and in small businesses.
Filament printers (FDM)
Fused deposition modelling (FDM), also called fused filament fabrication (FFF), melts a thin plastic thread called filament and pushes it through a hot nozzle. The nozzle traces each layer, then the printer moves up to build the next one. FDM is the most popular type of 3D printer. It works with the widest range of materials and makes strong, practical parts, including large ones.
Resin printers (MSLA / SLA)
Resin printers use ultraviolet (UV) light to harden liquid resin one layer at a time. Most consumer resin printers use a screen to flash the shape of a whole layer at once, a method known as MSLA. They produce exceptionally fine detail and smooth surfaces, which makes them ideal for miniatures, figurines, jewellery and dental models.
Other technologies exist, such as powder-based nylon printing (SLS) and metal printing, but manufacturers and print bureaus use these rather than home users. Not sure which type suits you? Read FDM vs resin 3D printers: which should you choose?
What can you make with a 3D printer?
Home and DIY
Replacement clips, brackets, knobs, hooks, cable tidies, organisers and custom-fit spare parts.
Business and prototyping
Product prototypes, design models, short production runs and customer-specific parts, made in hours rather than weeks.
Education and STEM
Classroom projects that bring design, engineering, science and art to life.
Hobbies and gaming
Tabletop miniatures, scale models, terrain, cosplay props and collectables.
Workshops and engineering
Jigs, fixtures, tool holders, assembly aids and replacement parts for machines.
Gifts and personalisation
Name plates, keyrings, lithophanes, ornaments and one-off personalised gifts.
Is 3D printing hard to learn?
Modern 3D printers are much easier to use than early machines. Many now calibrate themselves, level their own beds and come with slicer settings already tuned for their materials, so you can often get a good first print using the default settings.
There is still a learning curve. Expect a few failed prints at the start. They're a normal part of learning, and nearly all of them have simple causes, which we cover in common 3D printing problems and how to fix them. Most beginners are confidently printing their own projects within a few weeks.
How much does 3D printing cost to run?
The main up-front costs are the printer, your first materials and a few accessories. After that, running costs are modest. Small prints often use only a few grams of material, and a spool of filament or a bottle of resin will make many parts. Other running costs include electricity and the occasional replacement part, such as a nozzle, build plate or resin vat film.
Resin printing usually costs a little more per print than filament printing, because the material costs more and you also need cleaning fluid, gloves and other consumables.
How to use this guide
This guide is split into seven short parts. You can read them in order or jump to the one you need:
- 3D printing explained: what 3D printing is and how it works (this page)
- FDM vs resin: which type of printer to choose
- What you need: equipment, software and space
- Your first print: step-by-step instructions for both printer types
- Materials: choosing the right filament or resin
- Fixing problems: troubleshooting and maintenance
- Safety and glossary: staying safe and understanding the jargon
Frequently asked questions
Do I need to know CAD or 3D design to start 3D printing?
No. You can download ready-made 3D models from online libraries and print them straight away. Many people learn 3D design later, once they want to make their own parts, and there are free, beginner-friendly design programs to start with.
What is the best type of 3D printer for a beginner?
For most beginners, a filament (FDM) printer using PLA filament is the easiest place to start. It's clean, versatile and forgiving. If you mainly want highly detailed miniatures or figurines, a resin printer can be a good first choice, as long as you have a well-ventilated space and are happy to wear gloves and eye protection.
How long does a 3D print take?
It depends on the size of the object, the layer height, how solid you make it and the printer itself. A small, simple part can take under an hour, while a large or very detailed print can take a day or more.
Can a home 3D printer print metal?
Not true metal. Consumer printers print plastics and resins. Metal-filled filaments are available that look and feel metallic, but they're still mostly plastic. Solid metal printing uses industrial machines.
Can I print and sell any model I download?
Not always. Every model comes with a licence set by its designer. Many free models are for personal use only. Check the licence before printing a model to sell, and only print items that are legal to own in the UK.