---
title: "Vapor Smoothing for SLS Nylon Parts | AMT PostPro"
description: "Vapor smoothing SLS nylon and PP parts with PostPro: dimensional and burst-pressure results, materials by agent, and systems for desktop to industrial SLS."
canonical: https://amtechnologies.com/learn/sls-vapor-smoothing/
updated: 2026-10-07
type: learn
---
Learn · Selective laser sintering

# Vapor smoothing for SLS parts.

SLS vapor smoothing reflows the rough, porous surface of a selective laser sintered part into a smoother, sealed skin, with very little dimensional change: ≤ 0.4%[1] on SLS PA2200 in AMT’s published test. PostPro systems vapor smooth SLS parts in PA12, filled PA12, PA11 and polypropylene.[2]

[Test your parts, free](https://benchmarking.amtechnologies.com/submit?utm_source=amtechnologies.com&utm_medium=learn-page&utm_campaign=site-2026&utm_content=sls-sls-hero) [Get a price](https://amtechnologies.com/configurator/)

No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks[3]

Printing process

- **Dimensional change**: ≤ 0.4%[1]
- PA2200 · SLS
- **Burst pressure**: up to +7%[1]
- PA2200 · SLS
- **Materials**: PA12 · PA11 · PP[2]
- SLS rows, AMT brochure

Why SLS parts need finishing

## Laser-sintered nylon, with an open surface.

SLS nylon parts are tough and need no supports, from desktop systems to industrial machines. Their surface is grainy and porous, which limits them wherever a part must seal, clean or look finished.

1. ### Sealed

   Reflowing the surface closes its pores, so parts take up less water and dirt and can hold more pressure: up to +7%[1] burst pressure on SLS PA2200.
2. ### Accurate

   The skin reflows, not the whole part: dimensional change was ≤ 0.4%[1] on SLS PA2200.
3. ### Desktop to industrial

   The SFX and SF2X sit beside desktop SLS printers; the SF50 and SF100 take industrial build volumes.
4. ### Studied on desktop SLS

   AMT and Formlabs published a joint study of vapor smoothing on Formlabs SLS powders.

Published results

## What vapor smoothing measured on SLS parts.

Each result names the material it was measured on. Results depend on material, printer and recipe.

- Dimensions

  ≤ 0.4%[1]

  Dimensional change PA2200 · SLS
- Sealing

  up to +7%[1]

  Burst pressure PA2200 · SLS

[SLS PA2200 whitepaper](https://amtechnologies.com/resources/whitepapers/performance-improvements-of-vapour-smoothed-sls-pa2200-parts/) [Formlabs SLS study](https://amtechnologies.com/resources/whitepapers/enhancing-the-surface-quality-of-sls-3d-printed-parts-with-vapor-smoothing/) [Arkema PA11 SLS whitepaper](https://amtechnologies.com/resources/whitepapers/sls-printed-nylon-11-parts/)

Materials

## SLS materials by finishing agent.

Nylons run with PostPro Pure or FA326; polypropylene with FA9202.

**SLS materials by finishing agent**

| Material | PostPro Pure | FA326 | FA9202 |
| --- | --- | --- | --- |
| PA 12[2] | Listed | Listed | Not listed |
| PA 12 Filled[2] | Listed | Listed | Not listed |
| PA 11[2] | Listed | Listed | Not listed |
| Polypropylene[2] | Not listed | Not listed | Listed |

Partner · In April 2026, Raise3D announced a partnership with AMT to offer PostPro vapor smoothing to its RMS220 SLS customers in Europe.[4]

Which PostPro

## Which PostPro for your SLS printers.

Desktop systems next to desktop SLS, production systems for industrial builds. Every PostPro system lists PA12 and PA11.[5]

- Desktop SFX

  ### [PostPro SFX](https://amtechnologies.com/products/vapor-smoothing/postpro-sfx-desktop-vapor-smoothing-system/)

  Desktop vapor smoothing for R&D and low-volume production.[5]
- Desktop SF2X

  ### [PostPro SF2X](https://amtechnologies.com/products/vapor-smoothing/postpro-sf2x/)

  Vapor smoothing with double the chamber capacity of the PostPro SFX.[5]
- Production SF50

  ### [PostPro SF50](https://amtechnologies.com/products/vapor-smoothing/postpro-sf50/)

  Delivers end-use parts for low-volume production.[5]
- High volume SF100

  ### [PostPro SF100](https://amtechnologies.com/products/vapor-smoothing/postpro-sf100/)

  Vapor smoothing sized for high-volume production.[5]

[Help me choose](https://amtechnologies.com/configurator/) [See list prices](https://amtechnologies.com/pricing/)

Questions

## SLS vapor smoothing: questions.

Short answers from AMT’s published tests and material lists. Anything else, [ask an engineer](https://share.hsforms.com/1lOH82JpuRdSM-4wJ1ZeYlw45o6d?website_source=Vapor+Smoothing&utm_source=amtechnologies.com&utm_medium=learn-page&utm_campaign=site-2026&utm_content=sls-talk).

### Can SLS nylon parts be vapor smoothed?

Yes. SLS PA12, filled PA12 and PA11 run with PostPro Pure or FA326, and SLS polypropylene with FA9202.[2]

### How much do SLS parts change dimensionally?

Very little: ≤ 0.4%[1] on SLS PA2200 in AMT’s published test.

### Do filled SLS powders smooth?

Filled PA12 grades from SLS are listed with PostPro Pure and FA326.[2] Send a part in your grade to confirm the finish.

### Which PostPro suits a desktop SLS printer?

The desktop Desktop vapor smoothing for R&D and low-volume production.[5] The SF2X doubles its chamber; the SF50 and SF100 take industrial volumes.

Next step

## See the price. Run the numbers. Hold the part.

List prices are public and the cost-per-part math is yours to check, with no email needed for either. The free benchmark puts your own parts, vapor smoothed, in your hands.

1. 01 Quote

   ### Build your quote

   Pick a system and its options and get an itemized total on screen, from AMT’s published list prices.

   [Build your quote](https://amtechnologies.com/quote/)
2. 02 ROI

   ### Calculate your ROI

   Compare your cost per part with manual finishing, using your own labor rate and volumes. Every assumption is editable.

   [Calculate ROI](https://amtechnologies.com/roi/)
3. 03 Benchmark

   ### Test your parts, free

   Ship us your parts with a prepaid label. We vapor smooth them and send them back with before-and-after photos and a benchmark report.

   [Test your parts, free](https://benchmarking.amtechnologies.com/submit?utm_source=amtechnologies.com&utm_medium=learn-page&utm_campaign=site-2026&utm_content=sls-decision)

   No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks[3]

Prices: AMT list prices, excluding tax and shipping; confirmed in your formal quote.

[Not sure which system? Help me choose](https://amtechnologies.com/configurator/)

## Sources

1. [Performance improvements of vapor smoothed SLS PA2200 parts (whitepaper)](https://amtechnologies.com/resources/whitepapers/performance-improvements-of-vapour-smoothed-sls-pa2200-parts/) · AMT · Jan 8, 2024
2. [AMT PostPro brochure: automated post-processing systems for additive manufacturing, V4.0 (June 2026)](https://info.amtechnologies.com/download-document?document_name=brochure) · AMT · Jun 2026
3. [PostPro benchmarking: send us your 3D printed parts](https://benchmarking.amtechnologies.com/) · AMT · read Oct 6, 2026
4. [Raise3D announces partnership with AMT to bring advanced post-processing to RMS220 SLS 3D printer](https://amtechnologies.com/news/raise3d-and-amt-partnership/) · AMT · Apr 2, 2026 · also [3D ADEPT Media](https://3dadept.com/raise3d-and-amt-join-forces-to-deliver-end-to-end-sls-post-processing-in-europe/)
5. [Vapor smoothing: SF and X-series family page and SFX, SF2X, SF50, SF100 product pages](https://amtechnologies.com/products/vapor-smoothing/) · AMT · read Oct 6, 2026 · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sfx-desktop-vapor-smoothing-system/) · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sf2x/) · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sf50/) · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sf100/)