Less than six weeks after agreeing to buy on-demand manufacturing specialist Rapid Product Development Group, 3D Systems (DDD 0.88%) announced on Wednesday yet another acquisition, in the form of Phenix Systems, a company that specializes in making direct metal selective laser sintering 3-D printers.

More specifically, in Phenix Systems' words, it makes printers which can print "chemically pure fully dense metal and ceramic parts from very fine powders," including "stainless steel, tool steel, super alloys, non-ferrous alloys, precious metals, and alumina for a variety of aerospace, automotive a patient specific medical device applications."

According to the release, 3D Systems has signed agreements to purchase around 80% of Phenix Systems' outstanding shares at a maximum price of about 13 euros per share (or around $17). As a point of reference, that represents a 120% premium to Phenix's closing price of just $7.72 per share on France's Alternext stock exchange Tuesday. What's more, 3D Systems says the acquisition is "subject to customary closing conditions," after which, 3D Systems will launch a takeover bid on the remaining 20% of the shares of Phenix Systems.

Finally, and even though Phenix Systems posted a $2.5 million loss on just $6.1 million in revenue last year, 3D Systems indicated that those losses shouldn't continue long, as they expect the acquisition to be accretive to non-GAAP earnings in the first full year following the completion of the transaction. 

That's fair enough; remember, 3D Systems certainly has the resources to make the most of Phenix's technology, and simply owning the smaller company's presumably useful patents could, in itself, open up many possibilities for future innovation.

Who's next?
In total, as fellow fool Rich Smith pointed out yesterday, the acquisition should end up costing 3D Systems less than $20 million.

Considering I already noted that 3D Systems likely paid a similar amount for RPDG last month, that still still leaves plenty of room for future purchases. Remember, 3D Systems not only ended last quarter with more than $110 million in cash on its balance sheet, but also floated a new stock issue last month with the aim of raising around $250 million, largely for funding -- you guessed it -- additional acquisitions.

So who gets gobbled up next?

In all honesty, when we note the fact that many of 3D Systems' acquisition targets have been plucked from relative obscurity, I'm betting their next purchase will be no different -- a small, comparatively unknown business with complementary technologies.

That said, I suppose we shouldn't completely count out 3D Systems' up-and-coming competitor, MakerBot. Just a few days ago, the company was reportedly in acquisition talks with potential suitors; this information arose after MakerBot sought additional venture capital funding. Even so, I already expressed concern back in February that Makerbot's technologies could prove less complementary, and more repetitive, than anything else for 3D Systems' taste.

What's more, while TechCrunch also reported those potential acquirers could include one of 3D Systems' primary competitors in Stratasys, I still think the folks at Amazon.com (AMZN 3.25%) would do well to buy MakerBot, especially considering CEO Jeff Bezos's own venture capital firm has already invested in the company. In addition, that thesis was (at least partly) fulfilled this week, when Amazon also launched its own dedicated 3-D printing section on its site to cater to the growing additive manufacturing market.

Foolish final thoughts
In the end, if we can be sure of anything, it's that there's money to be made in the 3-D printing industry, which is currently experiencing incredible growth, and showing no signs of slowing down. Of course, with shares of 3D Systems currently trading at more than 102 times last year's earnings, investors are certainly paying a steep price for the opportunity to own a slice of the business.

Even so, the stock's forward P/E ratio is much more palatable at around 35 times earnings, so if the company can continue its torrid pace of expansion, it might just be able to grow into that valuation, and reward shareholders handsomely in the process.