Selective Laser Sintering

Selective laser sintering (SLS) is one of three additive processes available at Proto Labs. During the SLS process, a CO2 laser draws onto a hot bed of thermoplastic powder, where it lightly sinters (fuses) the powder into a solid. After each layer, a roller lays a fresh layer of powder on top of the bed and the process repeats. SLS uses a nylon-based powder similar to actual engineering thermoplastics, so parts exhibit greater toughness and are accurate, but have rough surface and lack fine details. SLS offers a large build volume, can produce parts with highly complex geometries and create durable prototypes.
1 to 50+ parts
Shipped in 1 to 7 days
Parts start at $95

Design Guidelines


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 selective laser sintering in nylon 12 (PA 650) material is 19 in. by 19 in. by 17 in. (482mm by 482mm by 431mm).
Fineline SLS part size


SLS parts are available in one resolution: layer thickness of 0.004 in. with a minimum feature size of 0.030 in. in most materials.


Typically, expected tolerances on well-designed parts are ±0.010 in. (0.25mm) or ±0.0015 in./in. (0.0015mm/mm), whichever is greater.


We offer numerous material options through our three additive processes 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. Four different types of nylon materials are available in SLS for different levels of stiffness and ductility.
See a full list of Proto Labs' materials.

Surface finishes

There are five standard finishes available through Proto Labs' 3D printing service, primarily geared towards stereolithography (SL) parts. SLS parts receive a standard finish involving a bead blast to remove all powder, which leaves a consistent overall texture.
Surface finishes
Fineline SLS surface finishes


We use multiple additive machines that offer large build sizes, accurate parts, and quick production times. For SLS, we use sPro140 machines, which have the world’s largest sintering build volume, and feature fully digital high-speed scanning systems, unparalleled process consistency, and closed systems for powder blending and delivery for reliable part quality. We also use SPro 60 machines, which allow for multiple materials and high throughput.