What is vapour smoothing?

Vapour smoothing is an automated post-processing technique that uses solvent vapour to melt and seal the outer surface of a 3D printed part, producing a smooth, glossy finish similar to injection moulding.

Is vapour smoothing better than traditional finishing for Nylon parts?

For most functional Nylon SLS parts, vapour smoothing is superior. It improves surface strength, water resistance, and aesthetics while reducing labour time and variability compared to manual sanding or painting.

Can vapour-smoothed parts be painted or dyed?

Yes. Nylon parts can be dyed before vapour smoothing or painted afterward for additional colour and protection, offering full design flexibility.

Is vapour smoothing suitable for all 3D printing materials?

Vapour smoothing works best on polymer materials such as Nylon PA12, PA11, and TPU. It’s primarily used for SLS and MJF 3D printed parts.

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Vapour Smoothing vs Traditional Finishing: Which is Better for Nylon Parts?

By Sam Gribben
October 22, 2025
12:00 pm

In the world of additive manufacturing, surface finish is more than just an aesthetic choice – it can directly affect part performance, durability, and even regulatory compliance. When it comes to Nylon SLS 3D printed parts, two primary finishing methods dominate the conversation: vapour smoothing and traditional finishing techniques such as sanding, tumbling, or painting. But which process delivers the best results for your application?

Vapour Smoothing vs Traditional Finishing: Which is Better for Nylon Parts? - vapour smoothing service,3D print finishing

Understanding Vapour Smoothing

Vapour Smoothing is an advanced post-processing method that uses controlled solvent vapour to smooth the surface of 3D printed parts. At SGD 3D, we use the AMT PostPro SFX system (click here to see our review) – a professional solution designed for SLS 3D printed Nylon PA12 and similar materials.

The process works by exposing the part to a fine vapour that gently melts the outermost layer of the polymer. This causes the surface to reflow, sealing microscopic pores and creating a uniform, glossy finish similar to injection-moulded plastic.

Key Benefits of Vapour Smoothing

Sealed, water-resistant surfaces

Enhanced mechanical strength and fatigue resistance

Improved cleanability and hygiene performance

Aesthetically smooth, semi-gloss appearance

Consistent results even for complex geometries

Unlike manual methods, vapour smoothing is fully automated and repeatable. It removes operator variation, allowing consistent surface quality from part to part – perfect for low-volume production or high-end functional prototypes.

Traditional Finishing Techniques

Before vapour smoothing, the industry relied heavily on traditional finishing processes such as bead blasting, sanding, tumbling, dyeing, and painting. These methods are still widely used today and can be very effective depending on the application.

For example, Painting allows you to achieve custom colours and surface effects, from matte industrial finishes to high-gloss consumer-grade coatings. Sanding or media blasting can also remove rough powder residues and slightly improve surface feel.

However, these approaches have limitations:

Manual labour increases production time and cost

Surface sealing is inconsistent

Fine internal features are difficult to access

Paint or coatings can chip, peel, or flake under stress

Repeatability varies between operators

For aesthetic prototypes or low-stress visual models, these techniques still make sense. But for performance-critical parts, vapour smoothing offers advantages that traditional methods can’t replicate.

Source: PDJ Vibro

Comparing the Two Methods for Nylon Parts

Let’s break down how Vapour Smoothing compares to Traditional Finishing for SLS Nylon components:

Property	Vapour Smoothing	Traditional Finishing
Surface Quality	Injection-mould-like smoothness	Varies depending on manual skill
Water Resistance	Fully sealed, impermeable surface	Porous and absorbent unless coated
Mechanical Strength	Increases tensile and fatigue strength	May reduce strength if over-sanded
Aesthetic Consistency	Uniform, repeatable results	Inconsistent between batches
Hygiene & Cleanability	Excellent – sealed against contaminants	Difficult to clean, retains residue
Labour & Time	Automated, low labour	Labour-intensive, high variability
Colour Options	Can be dyed pre-process or painted post-process	Wide range of paints, but less durable

Real-World Applications

Vapour smoothing has become the go-to method for industries such as medical, automotive, consumer goods, and aerospace, where both performance and appearance matter. For example, smooth and sealed SLS 3D printed enclosures used in outdoor or medical environments benefit from reduced bacterial adhesion and improved chemical resistance.

By contrast, traditional finishing still excels for artistic, decorative, or proof-of-concept projects where tactile surface feel or custom paintwork is more important than technical performance.

Why Vapour Smoothing Is the Future of Nylon Finishing

As SLS 3D printing continues to evolve from prototyping to full-scale production, the demand for professional post-processing grows. Vapour smoothing bridges that gap, offering a scalable, repeatable, and high-performance finish that matches the expectations of end-use manufacturing.

At SGD 3D, we combine vapour smoothing with our SLS Printing service to deliver production-grade Nylon PA12 and PA12 GF parts that are not only functional but ready for customer use straight out of the machine.

Whether you need sealed, smooth parts for medical devices, durable housings for electronics, or cosmetically enhanced components for consumer products, vapour smoothing is the superior choice.

Conclusions

In the debate between Vapour Smoothing and Traditional Finishing, both have their place. Traditional methods are versatile and accessible for short runs or aesthetic pieces, while vapour smoothing provides industrial-grade performance and repeatability.

For most Nylon SLS 3D printed parts, vapour smoothing offers the best balance of surface quality, durability, and scalability – making it the preferred option for professional production.

If you’re ready to take your 3D printed parts to the next level, explore our Vapour Smoothing service today and experience the difference.