As tech-savvy investors are no doubt aware, 3D printing is becoming increasingly mainstream. So much so, according to a recent Forbes article, that attention is shifting from the companies that manufacture 3D printers "to a broad range of industries where the technology is finding distribution and practical applications." Those include the automotive, financial and electronics industries, among others. It's thus not too surprising to hear that medical imaging component manufacturer Smit Röntgen, a Philips (NYSE: PHG) brand, has figured out a way to produce pure tungsten products using 3D printing. What is 3D printing? To understand what Smit Röntgen has done, it's useful to look briefly at what exactly 3D printing, also called additive manufacturing, entails. Put very simply, it's the process of creating a 3D object from a digital file. As its alternate name suggests, it's normally done through additive processes — essentially, a computer lays down layer upon layer of material until the object is built. In terms of what objects can be created, the variety is always growing. A CTV News article published earlier this month notes that while 3D printers been used to print "everything from medical devices to guns," some people have even more innovative plans — one Minnesota man plans to try to print a house. Printing with tungsten There are a variety of different 3D printing processes, but as Smit Röntgen states in a September 1 press release, it makes its pure tungsten products using a technique called powder bed laser melting. Essentially, that means it creates objects by "selectively solidifying thin layers of pure Tungsten." Explaining what the company is making, Harry Kleijnen, head of development, said, "Smit Röntgen is focused on creating added value to the industry by developing and manufacturing parts for medical applications, in particular high precision parts for X-ray collimation targeting the CT/PET/SPECT market." He added that the company has also "started to design and produce parts for industrial use."