A Brief History of Stereolithography

The SLA 3D printing process first appeared in the early 1970s, when Japanese researcher Dr. Hideo Kodama invented the modern layered approach to stereolithography, using ultraviolet light to cure photosensitive polymers. The term stereolithography was coined by Charles (Chuck) W. Hull, who patented the technology in 1986 and founded the company 3D Systems to commercialize it. Hull described the method as creating 3D objects by successively “printing” thin layers of a material curable by ultraviolet light.

SLA 3D printing, however, was not the first 3D printing technology to gain widespread popularity. As patents began to expire at the end of the 2000s, the introduction of small format, desktop 3D printing widened access to additive manufacturing, with fused deposition modeling (FDM) first gaining adoption in desktop platforms.

While this affordable extrusion-based technology sparked the first wave of wide adoption and awareness of 3D printing, FDM machines did not satisfy the spectrum of professional needs—repeatable, high-precision results are crucial for professional applications, as are biocompatible materials in the dental industry and the ability to create fine features for industries like jewelry and applications like millifluidics.

Prototypes of the Form 1, the first desktop SLA 3D printer.

Desktop SLA Printers Disrupt the Market

SLA printing soon followed FDM to the desktop, when Formlabs adapted the technology in 2011. Small format desktop SLA printers brought the promise of high resolution 3D printing—previously limited to monolithic industrial systems—in a much smaller and more affordable setup with a wide range of print materials. These capabilities expanded access to 3D printing for a variety of custom and high precision applications across disciplines, including engineering, product design, and manufacturing, as well as dental, jewelry, and other industries.

In 2015, Formlabs released its next generation resin 3D printer, the Form 2, which became the industry-leading desktop 3D printer, with parts printed in the field ranging from affordable custom prosthetics to a customizable line of razor handles.

The Form 2 reset the conversation for SLA 3D printing, popularizing a “distributed” model of production, where companies can scale output incrementally, adding more small format printers as demand increases with the flexibility to print in different materials on each printer. The maturity of materials over time has only increased the usage of this model, as more advanced resins have unlocked applications beyond prototyping and into production and end-use parts across industries.

In 2019, Formlabs made another step change in the industry with the launch of the Form 3 and Form 3L, two new hardware products that set a new standard for SLA with systems built on a completely new print process.

The Formlabs Form 3 and Form 3L are built on Low Force Stereolithography (LFS) 3D printing technology, an advanced form of SLA which uses a flexible tank and linear illumination to turn liquid resin into flawless prints.

The Next Chapter of SLA: Low Force Stereolithography 3D Printing

Low Force Stereolithography (LFS) technology is the next phase in SLA 3D printing, meeting the demands on today’s market for scalable, reliable, industrial-quality 3D printing.

This advanced form of SLA 3D printing drastically reduces the forces exerted on parts during the print process, using a flexible tank and linear illumination to deliver incredible surface quality and print accuracy. Lower print forces allow for light-touch support structures that tear away with ease, and the process opens up a wide range of possibilities for future development of advanced, production-ready materials.

Inverted SLA printing introduces peel forces that affect the print as it separates from the surface of the tank, so the build volume is limited and sturdy support structures are required. The Formlabs Form 2 is heavily calibrated to account for the forces of the peel process and produce high quality parts. Learn more about the differences between the Form 2 and Form 3, which uses LFS technology.