For most individuals or small design firms with digital fabrication needs, an affordable filament-based FDM (fused deposition modeling) machine is going to be the gateway drug into 3D printing. As profits increase, you may step up to an SLA (stereolithography) machine. But here's the thing: Even if you add an SLA 3D printer, you're probably not going to get rid of the FDM model. You'll find it still comes in handy for when you need to, say, quickly crank out multiple parts that don't require the precision and time of the SLA.

"Many businesses use both FDM and SLA machines alongside one another," writes Formlabs, who manufactures SLA machines like the Form 3, above. "This opens access to a wider range of applications supported by low-cost rapid prototyping, high quality, functional parts, and comprehensive material formulations."

To make their point--and hopefully a sale--the company's written up a "How to Optimize Projects With Both FDM and SLA Technologies" article interviewing folks who use both in their workflow. As one example, fabricator Matt Schmotzer, who produces working models of rollercoasters, takes the hybrid approach.

The support structures for the coasters require hundreds of individual members. "Since high detail quality is not a concern, and a large number of prints is required, Matt turns to FDM to quickly print most of the beams." The carriages, on the other hand, require much more detail. "The train models are printed on SLA machines [which] excel at creating final, high-quality end-use parts, and the train models are expected to look as realistic as possible down to the tiny handles on the doors."

You can read a couple more case studies at the article, but here's the main point: If you've got an FDM printer and are looking to add an SLA, Formlabs will knock up to $400 off of their SLA Form 3 printer. All you've got to do is provide proof that you own an FDM machine. If your model is on the list below, you're good to go:

To apply for your discount, click here. The offer's good until December 24th of this year.