Industrial 3D printing start-up Markforged announced earlier this month that it raised $30 million in a Series C funding round, which included "significant investments" from new investors Siemens-backed venture capital firm next47, Microsoft’s VC arm, and Porsche. Existing investors include VC firms Matrix, Trinity, and Northbridge. 

The new haul brings Markforged's total raise to $57 million.

The Boston area company is best known for making carbon-fiber 3D printers -- a capability possessed by neither of the two largest publicly traded 3D printing companies, 3D Systems (NYSE:DDD) and Stratasys (NASDAQ:SSYS). Moreover, Markforged touts that it's the only company that offers a 3D printing platform for producing parts from the complete range of materials from plastics to fiber-reinforced composites to metals.

Here's what you should know.

A Markforged X5 composite 3D printer with an out-of-focus view of a factory in the background.

An X5 3D printer for printing carbon fiber-reinforced plastics and other composites. Image source: Markforged.

Markforged's business

Markforged was founded in 2013 by CEO Greg Mark, an MIT-educated aerospace engineer and innovator in motorsports racing technology. The company gained fame for launching the first 3D printer that could print plastics reinforced with continuous carbon fiber. It also offers industrial 3D printers that can print in plastics, metals, and other composites, including plastics reinforced with fiberglass, Kevlar, or high-strength, high-performance (HSHP) fiberglass, along with a range of materials and cloud-based 3D printing software. 

The company recently launched two new composite printers, the X3 and the X5. It also recently shipped its first Metal X, which is powered by its proprietary Atomic Diffusion Additive Manufacturing (ADAM) tech, and can print in stainless steel, tool steel, titanium, and other metals.

Numerous entities -- including NASA, Google, Ford, Amazon, and Facebook -- across 50 countries reportedly use Markforged 3D printers for prototyping and to produce tooling and fixtures and end-use parts. Markforged says that customers, on average, see a return on investment in less than two months.

"The biggest barrier to human achievement is the length of time it takes to go from idea to physical product," the company said in its press release. "At Markforged we are unlocking a dramatic acceleration to change that process from years to days," added Greg Mark, founder and CEO. "With the new funding and strategic support from leading global manufacturing brands, we are poised to change the pace of human innovation."

Benefits and uses of carbon fiber-reinforced plastics (CFRP)

None of the publicly traded 3D printing companies offer 3D printers that can print in fiber-reinforced plastics. Moreover, while there are a fair number of 3D printers available that can print in plastics reinforced with chopped carbon, Markforged is in rarefied company when it comes to making machines that can print in plastics reinforced with continuous fiber.

Reinforcing plastics with carbon fiber -- particularly continuous fiber -- adds strength to a part while maintaining a lighter weight than metal. This feature makes it a great alternative to metals for certain applications within the aerospace industry and to make high-performance cars. 

Markforged is fast-growing and (gasp) profitable

Markforged has a trait that's in short supply among publicly traded pure-play 3D printing companies: It's profitable. The company -- whose revenue has increased 300% in 2017 year over year -- says it reached profitability in the second quarter of this year. None of the pure-play 3D printing companies that are listed on major U.S. stock exchanges (3D Systems, Stratasys, Materialise, ExOne, and voxeljet) are profitable on a trailing-12-month basis. However, Materialise -- which makes 3D printing software and provides 3D printing services -- has achieved sporadic quarterly profitability over the last couple of years.  

Investors can't buy stock in Markforged, since it's not publicly traded, but it seems only a matter of time before a larger player scoops it up or it goes public. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.