Molding (the manufacturing process, not the food spoilage one) has been around for a good six millennia, with a cast copper frog from 3200 B.C.E. being among the oldest surviving examples. The technique has adapted along with emergent technology throughout history, up to and including quick-set resins, CAD, and (as you saw here on SolidSmack last Friday) YouTube.

On the bleeding edge of fabrication tech, 3D printing suits molding particularly well. Ask Gabe Prero of Cufflink Junkie and, most recently, BioSpawn:

“…I took our iterative 3D designs, and using Solidworks, I split them, blocked off the backs, and made mating pegs so that all we’d need to do order the split mold-ready parts from Shapeways, slide them into pre-cut wood forms I had made, pour the silicone, peel it off, and then pour the lure plastic.”


The process is similar to Ann Sidenblad’s and Victoria Rose’s with RawrzToys, a line of customized mini toys with fans at MAKEzine, Mold3D, and Formlabs. In fact, the only real difference between these makers’ workflow is the step where 3D printing comes in: Prero sends Shapeways designs for the molds themselves, while Sidenblad prints her masters directly, and she and Rose create their own silicone molds from the 3D-printed parts.

BlogPost2Handcrafted prototyping versus Shapeways printed molds

In both cases, whether creating fishing lures or alligators in top hats, the creators stress the importance of the iterative flexibility that comes with the pairing of 3D printing and molding. “With one of our lures, we went through probably a dozen or so iterations, and the ability to turn these around with our sample mold process was integral to us hitting target deadlines,” says Prero.


With resins, plastics, castable silicone, and more on the market, and with the growing accessibility of 3D printing, it’s easier than ever to set up a workshop-scale precision molding/casting setup for quick modeling. CAD concepts can become physical objects in a few days, without the materials limitations sometimes imposed by printing. Finishing and customizing the end pieces can involve anything from mid-process pigment additions to spray paint, from grit polishing to hand painting with acrylics.

The jargon of molding and casting still involves some anachronisms–sprues, gangs, runners and gatings–but it’s clear the technology is keeping up with the times. Not bad for a method that’s past its 6000th birthday!

(Images via Gabriel Prero)