KANSAS CITY, Mo. Tim Middleton lives and breathes now, but the mind of the 42-year-old Eudora, Kan., man often floats to the future, to what one might call the printable life.
It is a time with tangible signs popping up with increasing frequency around the globe when nearly any product one needs is created by simply pushing a button and printing it out in usable three dimensions.
A pair of glasses? Print it.
A knee joint? Print it.
Red taillight lens for a '65 Mustang? Print it.
A birthday cake, a prom dress, a full-size house for a family of four? Print away.
"I have attempted printing my own shoes," Middleton said, laughing.
He is a graphic designer who in the past two years has instructed more than 60 people in the art and science of 3-D printing during Saturday classes at Hammerspace, a community workshop in Kansas City for builders, hobbyists and inventors.
"They're kind of hard," Middleton said of his shoes. "The material is a little uncomfortable. But it is absolutely a possibility."
More than possible: Such specialty 3-D-printed shoes already exist, produced and sold along with 3-D-printed nylon bathing suits, jewelry and dresses by Continuum Fashion of New York.
Cakes, cookies, sailboats, toys, architectural models, musical instruments, weapons, prosthetic hands and legs: All are items in recent years proved to be producible by 3-D printers.
Interest is high enough that the federal government last year earmarked $30 million to help support a new public-private institute in Youngstown, Ohio, dedicated to promoting and funding 3-D printing research.
It is a technology although already considered overhyped in some circles that many manufacturing experts say is only in its infancy, at a place similar to where personal and business computing was in the 1970s.
Like computing, they say, 3-D printing not only is likely to change the things we make and how we make and sell them, but also change how we live in good, bad and inconceivable ways.
"It is a bit tricky to predict," said Hod Lipson, a professor of mechanical engineering at Cornell University and co-author with Melba Kurman of "Fabricated: The New World of 3D Printing," a 2013 book on the promises and perils of an emerging technology.
"It is a little like trying to sit down in the 1970s and predict how computers were going to be used. Everyone could predict it would automate payrolls, but no one ever predicted social media."
Given that caveat, Lipson predicted of 3-D printing: "It is going to change everything."
Exactly when, how and how much, of course, is hard to say.
A May article in the New England Journal of Medicine described how two Michigan doctors used a 3-D printer to save an infant's life by printing a custom tracheal splint to support the baby's airway.
In the last year, meanwhile, one young man's mission to use a 3-D printer to produce a workable handgun sparked immediate outcry from the public and concerned government officials who envision the technology being used to put caches of cheap and untraceable guns into the hands of criminals or terrorists.
Business ethicist Kirk O. Hanson of Santa Clara University said improved technologies frequently usher in fresh fears. Better 2-D printing fostered high-grade counterfeiting. The Internet's role in money laundering continues to reveal itself.
Hanson said of 3-D printing: "This is simply the latest technological breakthrough that has great potential for good and great potential for harm."
Understanding 3-D printing and the future requires understanding how most products are made now.
The range is broad, from printing to stamping, casting to injection molding. Many manufacturing processes involve tooling or machining parts a subtractive process that produces a part by cutting or chipping or shaving away.
"You start with a block of material and subtract things until you get what you want," said Robert Landers, a professor of mechanical engineering at Missouri University of Science and Technology in Rolla.
But the first word in 3-D printing's alternative name, additive manufacturing, tells how it is different. Instead of chipping or cutting away at some material, a 3-D printer's nozzle runs back and forth, over and over again, oozing out layer after layer of whatever material is inside. It could be spools of plastic, metal, ceramic or cookie dough.
These printers have already been used to create a heart valve. Some predict the printers will use biological tissue to create entire replacement organs.
Instructions for what to build are guided by software, much of which is free online. The 3-D printer builds a whole object in place, as if it were growing from the bottom up. Or it creates parts of an object that can be assembled.
Printers can be small enough to fit on a desk, using spools of thermoplastic filament that looks like weed trimmer line. Or they can be huge, with nozzles pouring out stone-like material to create walls or 10-foot-tall sculptures.
3-D printing technology is not new. It first came to public notice in the early 1980s, and industries and scientists began toying and experimenting with it soon after. The airplane, automotive and other industries have used industrial 3-D printers for years to design and test specialty parts.
What is new is the growth in the industry, particularly in personal 3-D printers produced by companies such as 3D Systems Corp., MakerBot, Stratasys, MakerGear, FlashForge and Zen Toolworks.
In May, Staples became the first major U.S. retailer to announce it would soon be selling 3D Systems' Cube 3-D printer at its stores, beginning in Europe and also online, starting at $1,299.
Additive manufacturing and 3-D printing is a $2.2 billion industry, according to a 2013 report prepared by Wohlers Associates, an industry consulting group in Fort Collins, Colo. That is barely a speck compared with the $1.8 trillion generated by U.S. manufacturing last year.
But in 2010, 2011 and 2012, the global market for 3-D or additive manufactured products grew 24.1 percent, 29.4 percent and 28.6 percent respectively, according to the report. Sales last year of industrial 3-D printers (those costing $5,000 or more) grew 19.3 percent, which is nothing compared with the personal 3-D printer market: up more than 300 percent each year on average since 2008.
It's tempting to say the sky's the limit. In May, NASA awarded a $125,000 grant to an Austin, Texas-based company to hone a 3-D food printer. The idea is to use shelf-stable powders and oils to print, among other dishes, a pizza in outer space.