Stereolithography

Stereolithography (SL) is one of three additive processes available at Proto Labs. SL uses an ultraviolet laser focused to a small point to draw on the surface of a liquid thermoset resin. Where it draws, the liquid turns to solid. This is repeated in thin, two-dimensional cross-sections that are layered to form complex three-dimensional parts. SL provides the widest selection of material, best feature resolution and smoothest surface finish. It works well for very small parts and complex geometries during early prototyping.
1 to 50+ parts
Shipped in 1 to 7 days
Parts start at $95
PROCESS
DESIGN GUIDELINES

Design Guidelines

Size

With our additive processes, we’re able to deliver prototypes ranging from very small parts that meet extreme tolerance demands to large parts with precise patterns. Maximum build size for parts built by stereolithography is 29 in. by 25 in. by 21 in. (736mm by 635mm by 533mm).

Resolution

Proto Labs excels in high-quality precision parts that are available in three different SL resolutions:
Normal Resolution:
Layer thickness of 0.004 in. with minimum feature size of 0.010 in. for the XY draw plane (0.016 in. for the Z build direction)
High Resolution:
Layer thickness of 0.002 in. with minimum feature size of 0.005 in. for the XY draw plane (0.016 in. for the Z build direction)
Micro Resolution:
Layer thickness of 0.001 in. with minimum feature size of 0.0025 in. for the XY draw plane (0.008 in. for the Z build direction)
Resolution
Fineline SL normal resolution
Normal resolution
Fineline SL high resolution
High resolution
Fineline SL micro resolution
Micro resolution
Fineline SL normal resolution
Normal resolution
Fineline SL high resolution
High resolution
Fineline SL micro resolution
Micro resolution

Tolerances

For a well-designed part, tolerances in X/Y dimensions are ±0.002 in. (0.05mm) for the first inch plus ±0.001 in./in. (0.001mm/mm) for each additional inch. Z dimensions are ±0.005 in. (0.13mm) for the first inch plus ±0.001 in./in. (0.001mm/mm) for each additional inch. Note that tolerances may change depending on part geometry.

Materials

We offer numerous material options that are constantly updated to meet prototyping and master fabrication needs. Our materials offer many different characteristics: resolution, color and clarity, stiffness and feel, durability, impact resistance, temperature tolerance, and water resistance.
  • ABS-like
  • Polycarbonate-like
  • Polypropylene-like
  • SLArmor (nickel-plated)
See full list of materials

Surface finishes

There are three standard finishes within stereolithography:
Unfinished:
Dots, or standing “nibs,” remain evident on the bottom of the part from the support structure remnants.
Natural finish:
Supported surfaces are sanded down to eliminate the support nibs.
Standard finish:
Supported surfaces are sanded, and the whole part is finely blasted for a consistent look. Note that the layers are still present.
Surface finishes
Fineline surface finish-unfinished
Unfinished
Fineline surface finish-normal. SLA and 3D Printing
Natural
Fineline surface finish-standard
Standard
Fineline surface finish-unfinished
Unfinished
Fineline surface finish-normal. SLA and 3D Printing
Natural
Fineline surface finish-standard
Standard

Secondary options

Custom finishing — a service only offered within Proto Labs — is a mix of science, technology and fine art that can transform a part to your exact specifications. Custom finishes include:
  • Soft-touch paint
  • Clear part finishing
  • Paint finishes
  • Masking
  • Color matching
  • Decals/graphic
  • Texture
Secondary options
Fineline soft-touch paint
Soft-touch paint
Fineline clear part finishing
Clear part finishing
Fineline chrome finish
Chrome plating
Fineline paint finish
Paint finishes
Fineline masking finish
Masking
Fineline color matching finish
Color matching
Fineline decals-graphics finish
Decals/graphics
Fineline texture finish
Texture
Fineline soft-touch paint
Soft-touch paint
Fineline clear part finishing
Clear part finishing
Fineline chrome finish
Chrome plating
Fineline paint finish
Paint finishes
Fineline masking finish
Masking
Fineline color matching finish
Color matching
Fineline decals-graphics finish
Decals/graphics
Fineline texture finish
Texture

Special applications

In addition to our normal SL processes, we offer a few special applications unique to Proto Labs. Our SLArmor process takes stereolithography to the next level by finishing off an advanced ceramic-filled epoxy material from DSM Somos® (NanoTool™) with a metal coating that gives parts the look, feel and strength of metal, but without the weight. The combination of NanoTool’s extreme strength, rigidity and temperature resistance with SLArmor’s nickel plating, takes strength, stiffness and impact and temperature resistance to a degree previously unattainable in SL parts. In fact, the composite nature of the process gives SLArmor a greater strength-to-weight ratio than some metals.

Using the Proto Labs microfluidic fabrication process can allow you to dramatically shorten your development time for microfluidic devices of all shapes and sizes. If you intend to injection mold your microfluidic product, then the microfluidic fabrication process will allow you to design and test most features that you will employ in your injectionmolded product. This process eliminates the constraints created by the limitations of conventional or mask-less photolithography. Our microfluidic fabrication process is a modified form of high-resolution stereolithography that allows the creation of any 3D object(s) through a process of stacking two-dimensional layers of 50 microns thickness (0.002 in.). Stereolithography technology utilizes a liquid photopolymer that is polymerized into a solid by the application of ultra-violet light from a laser.
Special applications
Fineline SL Armor
SLArmor
Fineline microfludic fabrication
Microfluidic fabrication
Fineline SL Armor
SLArmor
Fineline microfludic fabrication
Microfluidic fabrication

Equipment

Proto Labs employs multiple additive machines that offer large build sizes, accurate parts and quick production times. Our stereolithography machines consists of Vipers, ProJets, and iPros. In high-resolution (HR) mode, Vipers and ProJets can make parts with extremely tiny features and crisp details, while in normal resolution (NR) mode, they can build cost-effective parts very quickly. iPros have build volumes that are truly huge at 29 in. by 25 in. by 21 in. (736mm by 635mm by 533mm), and yet are still able to image highly detailed parts easily.