You Asked: How Does 3-D Printing Work?

4 minute read

It’s not every day that 3-D printing will make people’s mouths water. But that was the case at the 2015 International CES, when XYZPrinting unveiled a device that can output icing and dough-based goodies like cookies.

This sweet development is the latest in a long, gradual history of innovation for 3-D printing, which goes back to 1983, when engineer-turned-entrepreneur Chuck Hull invented it in his spare time. Back then, Hull’s day job was curing rugged coatings onto tables using UV lights. But he postulated that focussing that light like a laser would allow the liquid resin with which he was working to form shapes. That was the basis for stereolithography (SLA), the advent of 3-D printing, and eventually the basis for his company, 3D Systems.

Today, 3-D printing essentially lets computer users take digital files and turn them into physical projects. If that sounds like paper or 2-D printing, that’s because they’re very similar. In 2-D printing, a file is created and sent to a printer, and a page is output. 3-D printing’s workflow almost exactly the same: a file is created and submitted to a device, the product is output, and it may require some finishing touches when done.

SLA is the earliest form of 3-D printing, and it’s very high quality. Originally used for what product developers call rapid prototyping, SLA was designed to give designers the ability to touch, feel, and compare the goods they were making. A slow-moving technology, it can take hours or days to print using SLA machines, which shines a laser into a pool of liquid, building the form layer-by-layer as a base support gradually moves the shape that’s being made. Despite this painstaking process, SLA’s quality is so good that you might never know your object was 3-D printed. SLA is used primarily only in commercial printing.

The 15 Most Bizarre Moments From the Consumer Electronics Show

A brand ambassador tests Samsung's Gear VR headset at the Samsung Galaxy booth at the International CES on Jan. 6, 2015, in Las Vegas.
A brand ambassador tests Samsung's Gear VR headset at the Samsung Galaxy booth on Jan. 6, 2015.Jae C. Hong—AP
Frank Lee, Brand Marketing for LG Electronics MobileComm USA, demonstrates the enhanced selfie feature on the new LG G Flex 2 mobile phone on press day for the 2015 International Consumer Electronics Show (CES) at the Mandalay Bay Convention Center in Las Vegas on Jan. 5, 2015.
Frank Lee, Brand Marketing for LG Electronics MobileComm USA, demonstrates the enhanced selfie feature on the new LG G Flex 2 mobile phone on Jan. 5, 2015. Michael Nelson—EPA
Attendees lay on Serta mattresses at the Serta stand on Jan. 6, 2015 at the Consumer Electronics Show in Las Vegas.
Attendees lay on Serta mattresses at the Serta stand on Jan. 6, 2015.Robyn Beck—AFP/Getty Images
Joe Clayton, CEO of Dish, arrives on stage banging a bass drum followed by company mascots during the Dish news conference at the International Consumer Electronics show (CES) in Las Vegas on Jan. 5, 2015.
Joe Clayton, CEO of Dish, arrives on stage banging a bass drum followed by company mascots during the Dish news conference on Jan. 5, 2015. Rick Wilking—Reuters
A transparent TRW model car is seen during the 2015 International Consumer Electronics Show (CES) in Las Vegas on Jan. 6, 2015.
A transparent TRW model car is seen on Jan. 6, 2015. Yang Lei—Xinhua Press/Corbis
At the 'Unveiled-event' a young woman has a look at salad at the CES electronics and consumer technology tradeshow in Las Vegas on Jan. 4, 2015.
At the 'Unveiled-event' a young woman has a look at salad on Jan. 4, 2015. Britta Pedersen—dpa/Corbis
The drone'Nano' from 'Zano' on Jan. 8, 2015.
The drone 'Nano' from 'Zano' on Jan. 8, 2015. Britta Pedersen—dpa/Corbis
Attendees interact with wity screens that run on Intel's Realsense technology on Jan. 6, 2015.
Attendees interact with wity screens that run on Intel's Realsense technology on Jan. 6, 2015.Michael Nelson—EPA
An attendee wears Altspace Virtual Reality head ware on Jan. 6, 2014.
An attendee wears Altspace Virtual Reality head ware on Jan. 6, 2014.Michael Nelson—EPA
Sony Electronics President and COO Mike Fasulo displays the Sony 4K Action Cam at a press event on Jan. 5, 2015.
Sony Electronics President and COO Mike Fasulo displays the Sony 4K Action Cam at a press event on Jan. 5, 2015.David Becker—Getty Images
Consumer Electronics Association President and CEO Gary Shapiro exits a Mercedes-Benz F 015 autonomous driving automobile after it was unveiled at a Mercedes-Benz press event on Jan. 5, 2015.
Consumer Electronics Association President and CEO Gary Shapiro exits a Mercedes-Benz F 015 autonomous driving automobile after it was unveiled at a Mercedes-Benz press event on Jan. 5, 2015.David Becker—Getty Images
A display shows Panasonic's virtual make-up mirror at a Panasonic news conference on Jan. 5 , 2015.
A display shows Panasonic's virtual make-up mirror at a Panasonic news conference on Jan. 5 , 2015.Steve Marcus—Reuters
Selfie sticks of the company 'Noosy' displayed on Jan. 8, 2015.
Selfie sticks of the company 'Noosy' displayed on Jan. 8, 2015.Britta Pedersen—EPA
World freediving champion Stig Severinsen holds his breathe underwater for a total of 5 minutes, 35 secs to demonstrate the functionality and accuracy of the Masimo SET pulse oximetry device on Jan. 8, 2015.
World freediving champion Stig Severinsen holds his breathe underwater for a total of 5 minutes, 35 secs to demonstrate the functionality and accuracy of the Masimo SET pulse oximetry device on Jan. 8, 2015.Robyn Beck—AFP/Getty Images
Workers install an advertisement for a new S'UHD TV from Samsung Electronics on the side of the Las Vegas Convention Center on Jan. 4, 2015.
Workers install an advertisement for a new S'UHD TV from Samsung Electronics on the side of the Las Vegas Convention Center on Jan. 4, 2015.Steve Marcus—Reuters

Another kind of 3-D printing is Selective Laser Sintering (SLS). “Selective Laser Sintering is a powder and laser type technology, but boy doesn’t that sound similar to toner and laser technology that’s used in a photocopy?” says John Hauer, founder of 3DLT, a company that prints 3-D products for retailers. And in essence SLS is very similar to a laser printer, only instead of scoring the toner onto a piece of paper, this three-dimensional technology shines its laser onto a bed of powder, turning it into hardened material. Also primarily a commercial technology, SLS can be used in many ways, allowing people to produce products in everything from nylon-based plastics to metals, including stainless steel, silver, gold, and titanium.

The third major kind of 3-D printing, Fuse Deposition Modeling (FDM), is the one that’s making the most waves with consumers right now. “That is what people envision as kind of like weed whacker string, where a plastic is inserted into a hot end and then melted, layer by layer, to achieve the product,” says Hauer. And to continue the paper printing analogy, FDM is also very similar to inkjet printing, where ink is extruded through a print head onto a page.

While this technology is getting better all the time, it still, literally, has some rough edges. But Hauer says some people like that. “You can feel the ridges—you can scrape your thumb along it and it’ll actually make a sound,” he says. “Because people are so interested in 3-D printing, the ability to touch and feel a 3-D printed product and tactilely know it’s different than a mass produced product has actually been advantageous. It’s helped them better understand the technology.”

And of course, food is something that everyone understands, which is why the edible printing technology made such big headlines at CES. Our future holds chocolate flowers, elaborate cake toppers, crazy confectionaries and other exciting edibles, says Hauer. “It has the opportunity to be a big thing,” he says. “We’ve even seen 3-D printed cheese, 3-D printed peanut butter and some of those things.”

But the real question is, will 3-D printed doughnuts taste as good as the real thing?

See Photos of Europe's Largest 3D Scanner

Martin Benes from 3D gang company demonstrates one of the stages of 3D scanning on August 26, 2014 in Prague, Czech Republic. The 3D scanner is the largest in continental Europe, with 115 sensors, and is designed to scan objects, people and animals.
Martin Benes from 3D gang company demonstrates one of the stages of 3D scanning on August 26, 2014 in Prague, Czech Republic. The 3D scanner is the largest in continental Europe, with 115 sensors, and is designed to scan objects, people and animals. Matej Divizna—Getty Images
Martin Benes from 3D gang company is seen through the viewfinder as he demonstrates one of the stages of 3D scanning on August 26, 2014 in Prague, Czech Republic.
Martin Benes from 3D gang company is seen through the viewfinder as he demonstrates one of the stages of 3D scanning on August 26, 2014 in Prague, Czech Republic. Matej Divizna—Getty Images
Europe's Largest 3D Scanner
Martin Benes works with a 3D model on the computer on August 26, 2014 in Prague, Czech Republic. Matej Divizna—Getty Images
Europe's Largest 3D Scanner
Martin Benes works with a 3D model of himself on the computer on August 26, 2014 in Prague, Czech Republic. Matej Divizna—Getty Images
Europe's Largest 3D Scanner
Martin Benes from 3D gang company holds a printed figurine of himself on August 26, 2014 in Prague, Czech Republic. Matej Divizna—Getty Images
Europe's Largest 3D Scanner
Martin Benes from 3D gang company demonstrates one of the stages of 3D scanning on August 26, 2014 in Prague, Czech Republic. Matej Divizna—Getty Images
Europe's Largest 3D Scanner
Printed figurines stand on display at the 3D gang company on August 26, 2014 in Prague, Czech Republic. Matej Divizna—Getty Images

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