SLS Materials: Complete Guide to SLS Nylon and Other SLS Printing Materials

If you’ve been exploring additive manufacturing, you’ve probably noticed that SLS materials dominate many real-world applications—from automotive parts to consumer electronics. And for good reason. SLS offers excellent strength, precision, and freedom of geometry, but the material you choose plays a huge role in how your final part performs.

This guide walks you through the essentials: what SLS materials are, why SLS nylon leads the pack, what other options exist, and how to choose the right material for your project.

What Are SLS Materials?

SLS (Selective Laser Sintering) materials are powders engineered to melt and fuse together when exposed to a laser inside an SLS printer. Instead of printing with filaments or liquid resins, SLS uses powder-bed fusion, which allows for:

• complex geometries
• no support structures
• strong mechanical properties
  
  

Most SLS printing materials are thermoplastics—especially nylons—but the technology now supports everything from elastomers to composites.

Definition Reminder: Nylon Powder for SLS
A finely controlled thermoplastic powder formulated specifically for SLS printing. Common examples include PA12 and PA11.

Your choice of powder determines not only the strength of your part, but also surface finish, flexibility, and long-term durability.

SLS Nylon (PA12, PA11) – The Most Popular SLS Printing Materials

If SLS had a “default material,” it would be nylon powder—specifically PA12 and PA11. These two polyamides offer a near-perfect balance of strength, detail, and reliability.

Why SLS nylon dominates:

• Excellent mechanical strength
• High abrasion and fatigue resistance
• Good stability over time
• Smooth, consistent surface finish
• Reliable printing with low failure rates
  
  

PA12 (Nylon 12): the all-rounder

PA12 is the most widely used nylon powder for SLS, known for its stiffness, durability, and dimensional precision. It’s ideal for:

• housings
• connectors
• mechanical prototypes
• small-batch production parts

PA11 (Nylon 11): the flexible performer

PA11 is slightly more flexible and impact-resistant than PA12. It’s also bio-based, made from castor oil, which appeals to users seeking more sustainable materials.

It’s often chosen for:

• hinges
• dynamic parts
• wearables
• components exposed to repeated bending

Together, PA12 and PA11 make up the majority of SLS nylons used today.

Other SLS Printing Materials You Should Know

While nylon leads the field, the universe of SLS materials is growing fast. Here are some notable alternatives:

TPU (Thermoplastic Polyurethane)

A flexible, rubber-like material known for its elasticity and durability. Great for gaskets, protective gear, and shock-absorbing components.

PP (Polypropylene)

Lightweight, chemically resistant, and semi-flexible. Popular in automotive and consumer goods.

PA6 and PA6 composites

Higher temperature resistance compared to PA12, often reinforced with fibers for extra stiffness.

Carbon- or glass-filled nylons

Blends of nylon with chopped fibers to improve strength and rigidity for engineering applications.

These additional materials expand what’s possible with SLS, from soft elastomers to high-performance composites.

How to Choose SLS Printer Materials for Your Project

Selecting the right SLS printer materials starts with defining what your part actually needs to do. Ask yourself:

• Does the part need to be rigid or flexible?
• Will it experience mechanical stress or fatigue?
• Does it require chemical resistance?
• How important is surface finish?
• Will the part be used outdoors or in high-heat environments?
  
  

For example:

• Rigid housings or brackets? → PA12
  
  
• Flexible hinges or wearable parts? → PA11 or TPU
  
  
• High stiffness? → Glass-filled or carbon-filled nylon
  
  
• Chemical exposure? → PP
  
  

Matching material properties to your application ensures you get the performance you expect.

Material Properties to Compare Before Printing

Before selecting your powder, compare the key SLS material properties:

1. Tensile strength

Describes how much pulling force an SLS-printed part can withstand before it breaks.

2. Elongation at break

Measures how much the material can stretch before it fails. Indicates flexibility—higher numbers mean more stretch. 

3. Heat resistance

Indicates the maximum temperature a printed part can endure without deforming. Critical for automotive or outdoor environments.

4. Surface finish & detail resolution

This refers to how smooth the printed surface is and how well fine features are reproduced.Finer powders often produce smoother surfaces.

5. Density and weight

Some materials are lighter or more rigid depending on particle composition.

6. Reusability/refresh rate

Describes how much used powder can be mixed with fresh powder while maintaining print quality.

When you know these properties, you’re not picking materials by name anymore—you’re choosing them for what they can do. That means stronger parts, smarter decisions, and better results.

SLS Materials: Cost, Availability, and Supplier Differences

Not all SLS printing materials cost the same. Prices vary based on:

• purity
• particle size distribution
• mechanical performance
• supplier brand
• certifications (e.g., medical or aerospace)
  
  

General cost expectations:

• Standard PA12 powders → mid-range pricing
• PA11 & composite nylons → slightly higher
• TPU and specialty polymers → variable
• Reinforced powders → highest cost
  
  

Availability also differs by region and supplier. Some materials are easy to source worldwide, while others are limited to specific markets or printer ecosystems.

If you’re using an open-material SLS printer, you’ll have the broadest selection.

FAQ = Quick Recap of the Main Points

What are SLS materials?

They are powders used in Selective Laser Sintering, designed to melt and fuse together under a laser.

What is the most popular SLS printing material?

PA12 and PA11—commonly referred to as SLS nylon.

Why is nylon powder for SLS so common?

Because it offers excellent strength, durability, and predictable printing behavior.

Can SLS printers use flexible materials?

Yes—TPU and PA11 are common choices for flexible parts.

What’s the difference between PA11 and PA12?

PA11 is more flexible and impact-resistant, while PA12 is stiffer and more precise.

Are reinforced SLS materials stronger?

Fiber-filled nylons offer increased stiffness and are used for engineering applications.

How do I choose SLS materials for my project?

Match your material to your part’s requirements: rigidity, flexibility, heat, chemicals, or durability.

Does every SLS printer support all materials?

No—some printers are open-material, while others are optimized for specific powders.

Are SLS printing materials expensive?

Standard nylons are mid-range, while composites and specialty polymers cost more.

Is nylon powder reusable?

Most SLS nylons can be recycled with a certain refresh rate, depending on the supplier.