Skip to content

Guide to Understanding SLA (Stereolithography) 3D printing

As the range of available technologies continues to expand, it’s natural that more questions arise. That’s why the Additive Plus team is here to provide you with guidance on when to use SLA technology for your projects.
SLA technology, also known as Stereolithography, is a well-established method for prototyping and low-volume manufacturing.

So, what exactly is SLA technology? It’s a 3D printing technique that was developed by 3D Systems in the 1970s, and it was the first industrial-grade approach to 3D printing. The maturity of this technology is crucial, particularly given the numerous alternatives
available for different materials. Its greatest strength lies precisely in its maturity.

How does SLA technology work?

SLA technology uses a laser which is in the ultraviolet spectrum around 355nm, to target a thin >0.1mm layer of photosensitive resin. Photopolymerization occurs when the laser hits the resin and it solidifies. By solidifying layer by layer of resin, it is possible to create complex geometries with an extremely high degree of precision.

What are the advantages of SLA printing?

Higher level of detail compared to other 3D printing technologies: Resolution of 0.02mm in XY and 0.13mm in Z.

Extensive range of materials comparable to technologies like FFF, including polymeric resins such as ABS-like, Nylon-like, and Rubber,-like as well as other resins commonly used in industries such as Wax, Ceramic, and Metal.

Ideal technology for both very small parts in jewelry-making and large-scale pieces in fields like animation, sculpture, and automotive.

Very fast printing speed; SLA technology can achieve 3D prints in remarkably quick times
compared to other manufacturing methods.

Smooth surface finish that eliminates the need for complicated post-processing.

How does this technology compare to others?

It is important to consider the strengths and limitations of each method. While each technology has its own unique applications and benefits, it’s worth noting that this comparison is not meant to suggest that one technology is superior to another in every aspect. Rather, we include it to emphasize the strengths of each technology.

Resolution and precision

SLA is a printing process that is known for its high resolution and precision. This makes it the perfect choice for printing designs that require fine details and smooth surfaces.

FFF, on the other hand, generally offers lower resolution compared to SLA. As a result, the surfaces may be rougher, and the details may be less defined.

SLS, another popular printing process, provides good resolution and precision, although it may vary depending on the machine’s setup. Generally, it offers better resolution than FDM but may not be as high as SLA.


SLA: It uses liquid resins that can offer a wide range of properties such as flexibility, hardness, and transparency.

FDM: It primarily uses thermoplastic filaments, which limits the variety of materials available compared to SLA.

SLS: It can use a variety of thermoplastic powders, allowing it to print in a broader range of materials compared to FDM, although the variety may be more limited than that of SLA.




Printing time

SLA: It can have faster printing times and achieve more details due to its high resolution and quick curing process. More lasers can be added to the process to achieve higher printing speeds while maintaining high resolution.

FDM: Generally, it has longer printing times due to its layer deposition process, and depends on 1 extrusion head for all the process.

SLS: Printing times can vary depending on the size and complexity of the part but tend to be in the mid-range compared to SLA and FDM. More lasers can also be added to this process to improve printing speed. However, the productivity of SLS is unbeatable thanks to the possibility of printing without supports and the ability to nest as many parts as the build volume allow to.


SLA: Printed parts typically require minimal post-processing in terms of support removal and sanding, as the surfaces are usually smooth directly from the printer.

FDM: Often requires more post-processing to remove layer marks and supports, which may require sanding and additional finishing.

SLS: May require less post-processing than FDM but more than SLA, as parts may have arougher surface texture.

If you require more information about SLA technology or any other 3D printing technology, Additive Plus can provide complete assistance ranging from design and prototyping to high-volume manufacturing.
Additive Plus is an expert in SLA technology, having been in the industry for over 10 years and installed dozens of SLA printers in the United States.
At Additive Plus, we offer 3D printing services in SLA and distribute the Kings 3D printing systems in the United States. We work with large-format parts in our plant in Santa Fe Springs, CA, and produce on-demand batches of parts with excellent quality with short lead times.
We have a wide range of materials for SLA printing that ensure excellent surface finish, combined with consistent and highly accurate dimensional accuracy for engineering and design projects. We also provide comprehensive solutions from CAD design, 3D scanning, and 3D printing.