They're not your granddad's daisy wheel printer, or your mom's dot matrix. In fact, they bear little resemblance to today's document or photo printers, which can only print in boring old two dimensions. As their name suggests, 3D printers can build three-dimensional objects, out of a variety of materials. They're going mainstream, showing up at retailers such as Staples, Best Buy, and Home Depot, and you can buy numerous 3D printers and their supplies on Amazon.com and through other online outlets. Though still mostly found on shop floors or in design studios, in schools and community centers, and in the hands of hobbyists, 3D printers are increasingly being found on workbenches, in rec rooms, and kitchens—and perhaps in a home near you, if not your own.

What Is 3D Printing?

At its most basic, 3D printing is a manufacturing process in which material is laid down, layer by layer, to form a three-dimensional object. (This is deemed an additive process because the object is built from scratch, as opposed to subtractive processes in which material is cut, drilled, milled, or machined off.) Although 3D printers employ a variety of materials (such as plastic or metal) and techniques (see "How Does 3D Printing Work?" below), they share the ability to turn digital files containing three-dimensional data—whether created on a computer-aided design (CAD) or computer-aided manufacturing (CAM) program, or from a 3D scanner—into physical objects.

Is 3D Printing Even Printing?

Yes, 3D printing can be considered printing, although not as it's traditionally been defined. The relevant Webster's definitions of "printing" center on the production of printed matter, publications, or photographs, and producing by means of impression (the application of pressure). Neither definition really fits 3D printing. But from a technological perspective, 3D printing is an outgrowth of traditional printing, in which a layer of material (usually ink) is applied. Usually it's so thin that there is no noticeable height (though with solid ink printers, it is somewhat thicker). What 3D printing does is greatly extend that height through the application of multiple layers. So it would make sense to expand the definition of printing to include the fabrication of three-dimensional objects in this manner.

How Does 3D Printing Work?

Much like traditional printers, 3D printers use a variety of technologies. The most commonly known is fused deposition modeling (FDM), also known as fused filament fabrication (FFF). In it, a filament—composed of acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), or another thermoplastic—is melted and deposited through a heated extrusion nozzle in layers. The first 3D printers to come to market, made in the mid 1990s by Stratasys with help from IBM, used FDM (a term trademarked by Stratasys), as do most 3D printers geared to consumers, hobbyists, and schools.

Another technology used in 3D printing is stereolithography. In it, a UV laser is shined into a vat of ultraviolet-sensitive photopolymer, tracing the object to be created on its surface. The polymer solidifies wherever the beam touches it, and the beam "prints" the object layer by layer per the instructions in the CAD or CAM file it's working from.

In a variation on that, you also have digital light projector (DLP) 3D printing. This method exposes a liquid polymer to light from a digital light processing projector. This hardens the polymer layer by layer until the object is built, and the remaining liquid polymer is drained off.

Multi-jet modeling is an inkjet-like 3D printing system that sprays a colored, glue-like binder onto successive layers of powder where the object is to be formed. This is among the fastest methods, and one of the few that supports multicolor printing.

It's possible to modify a standard inkjet to print with materials other than ink. Enterprising do-it-yourselfers have built or modded print heads, generally piezoelectric heads, to work with various materials—in some cases printing out the print heads themselves on other 3D printers! Companies like MicroFab Technologies sell 3D-capable print heads (as well as complete printing systems).

Selective laser sintering (SLS) uses a high-powered laser to fuse particles of plastic, metal, ceramic, or glass. At the end of the job, the remaining material is recycled. Electron beam melting (EBM) uses—you guessed it—an electron beam to melt metal powder, layer by layer. Titanium is often used with EBM to synthesize medical implants, as well as aircraft parts.

Depending on the technique, 3D printers can use a variety of materials, including but not limited to metals (stainless steel, solder, aluminum, and titanium among them); plastics and polymers (including composites that combine plastics with metals, wood, and other materials); ceramics; plaster; glass; and even foodstuffs like cheese, icing, and chocolate! (See our primer on 3D printer filament types.)

Who Invented 3D Printing?

The first 3D printer, which used the stereolithography technique, was created by Charles W. Hull in the mid-1980s. Stereolithography has traditionally been an expensive commercial technique, with machines costing in the five and even six figures, but recent years have seen the advent of desktop professional stereolithography printers costing a few thousand dollars, as well as consumer systems that start well under a grand.

In 1986, Hull founded 3D Systems, a company that today sells 3D printers that use a variety of technologies. They range from entry-level kits to advanced commercial systems, and 3D Systems also provides on-demand parts services, mostly to business users.

What Are the Benefits of 3D Printing?

With 3D printing, designers have the ability to quickly turn concepts into 3D models or prototypes (a.k.a. "rapid prototyping"), and implement rapid design changes. It lets manufacturers produce products on demand rather than in large runs, improving inventory management and reducing warehouse space. People in remote locations can fabricate objects that would otherwise be inaccessible to them.

From a practical standpoint, 3D printing can save money and material versus subtractive techniques, as very little raw material is wasted. And it promises to change the nature of manufacturing, eventually letting consumers download files for printing even complex 3D objects—including, for example, electronics devices—in their own homes.

What Can 3D Printers Make?

Designers use 3D printers to quickly create product models and prototypes, but they're increasingly being used to make final products, as well. Among the items made with 3D printers are shoe designs, furniture, wax castings for making jewelry, tools, tripods, gift and novelty items, and toys. The automotive and aviation industries use 3D printers to make parts. Artists can create sculptures, and architects can fabricate models of their projects. Archaeologists are using 3D printers to reconstruct models of fragile artifacts, including some of the antiquities that in recent years have been destroyed by ISIS. Likewise, paleontologists and their students can duplicate dinosaur skeletons and other fossils. Check out our gallery of simple and practical 3D printer objects.

Physicians and medical technicians can use 3D printing to make prosthetics, hearing aids, artificial teeth, and bone grafts, as well as replicate models of organs, tumors, and other internal bodily structures from CT scans in preparation for surgery. A good example is Project Daniel, which 3D-prints prosthetic arms and hands for victims of the violence in Sudan. Also, 3D printers being developed that can lay down layers of cells to create artificial organs (such as kidneys and blood vessels) are already in the R&D phase. There's even a place for 3D printing in forensics, for example to replicate a bullet lodged inside a victim.

Printed electronics is a set of printing methods that enable electronic devices or circuitry to be printed on flexible material such as labels, fabrics, and cardboard, by application of electronic or optical inks. It provides very low-cost fabrication of low-performance devices. Printed electronics is beginning to be combined with 3D printing, allowing for the printing of layered circuitry or devices. A natural outgrowth of this potent combo is that someday you may be able to print out gadgets from 3D plans rather than buying them.

Food preparation is another way 3D printers can be used. The French Culinary Institute has been using a [email protected] open-source 3D printer developed at Cornell University to prepare artistic delicacies, and MIT has created a 3D food printer called the Cornucopia. A small number of restaurants are testing food-printer prototypes. NASA's 3D printing research has included food printing, such as 3D-printed pizza.

A handful of food 3D printers have become commercially available. They tend to focus on particular food items, like chocolate, or pancakes, or cookies.

What Are 3D Printing Services?

You don't have to own a 3D printer to benefit from one. Many 3D printing services, such as Shapeways and Sculpteo, print gifts and other small items on order on their own 3D printers, then ship them to the customer. Customers can either submit their own 3D object files or choose items, most of them designed by other users of the service, from an online catalog.

But 3D printing services are no longer solely the domain of specialists. Large companies such as UPS have introduced 3D printing services, and some traditional print shops have added on-demand 3D printing to their repertoire.

Where Can I Get a 3D Printer?

Most 3D printer manufacturers sell their products directly online. Many e-tailers now stock them, including online-only companies such as Amazon.com, and others that also have brick-and-mortar stores. Some of the latter, such as Walmart, Best Buy, and Staples, offer them in stores as well as online, but be sure to check for store availability on their websites as not all outlets carry them. Several 3D printer stores have opened in major cities. For instance, iMakr has storefronts in London and New York City.

A few online retailers specialize in 3D printers, such as Dynamism, which sells a range of 3D printers from different brands and also provides customer support.

What Software Do I Need for 3D Printing?

Nearly all 3D printers accept files in what's called STL format (named for stereolithography). These types of files can be produced by most any CAD software, from expensive commercial packages like AutoCAD to free or open-source products such as Google SketchUp and Blender. For those not inclined to make their own 3D files, 3D object databases such as MakerBot's Thingiverse offer numerous 3D object files that can be downloaded and printed out.

Most 3D printers come with a software suite, either supplied on disk or available for download, that includes everything you need to get printing. The suites typically provide a program for controlling the printer and a slicer, which, in preparation for printing, formats the object file into layers based on the selected resolution and other factors. Some suites include a program to "heal" the object file by correcting problems that could interfere with smooth printing. The programs came out of the RepRap open-source movement, out of which hobbyist 3D printing developed. With some printers, you can choose the individual component programs to download rather than going with whatever is provided in the suite.

What Does the Future Hold for 3D Printing?

A variety of 3D printers for homes and small businesses is readily available—PCMag has reviewed quite a number of them—but they are still often viewed as exotic, and rather pricey, contraptions. Expect that to change within the next few years, when 3D printers will become more commonplace in houses—to be found on workbenches, in studios, in home offices, and even in the kitchen. You may not find them in every household, but they'll become indispensable to those people who do have them. For the most part, items made with 3D printers have had homogenous interiors, but we'll start to see more complex creations combining multiple materials and composites, as well as printable electronics. With today's 3D printers, if you lose your TV remote's battery cover, it may be possible to print a replacement cover. With tomorrow's, if you lose your remote, perhaps you'll be able to print a whole new remote.

Also, 3D printing is gaining a foothold in outer space. NASA is experimenting with 3D printers on board the International Space Station. Eventually, 3D printers could be used to create habitats on Mars and other worlds. To save the Apollo 13 astronauts from dying of carbon monoxide asphyxiation, NASA had to in effect find a way to fit a square peg into a round hole. Had there been a 3D printer on board, they may have been able to easily solve the problem by designing and printing a connector.

Astronauts can't take a swing by Home Depot if they need to replace a valve or widget, but a 3D printer could fabricate one as needed. Likewise, we'll see 3D printers in Antarctic bases and other remote Earthly locations, where folks can't wait six months for the next resupply to replace essential parts or tools.

Medical applications of 3D printing don't stop with prosthetics, hearing aids, and dental crowns. (See "What Can 3D Printers Make?" above for a preview of what's in the works.) Replacement parts needn't be restricted to the mechanical.

The past few years, we have seen an explosion in the variety and uses of 3D printers. It's similar to where personal computing was circa 1980. Though it's easy enough to see some of the areas the field of 3D printing will branch into, others are beyond our ability to predict, just as no one around in 1980 could have imagined much of what the personal computer would turn into. It's possible that 3D printing may not have the same impact as the PC on a consumer, everyday-life level, but it does have the potential to revolutionize manufacturing and, perhaps more important, bring it into the hands of everyday consumers. One thing's for sure, though: 3D printing is here to stay.

Which 3D Printers Should I Look At, for Starters?

For deeper coverage of individual printers, and how to buy one, check out our guide to the 10 best 3D printers, and some insights from an early adopter. But some quick picks to check out...

For Basic Experimentation With 3D Printing...

For Beginners Short on Space...

For Lots of Choice in Filament Types...

For 3D Printing in Two Colors...

For Product Design, Engineers, or Serious Hobbyists...

Further Reading

3D Printer Reviews