Adding Colour to SLS: Functional and Aesthetic Advantages of Dyed 3D Parts

Tuesday 24th June 2025

SLS 3D printed parts are typically produced in white or grey Nylon with a high-quality surface finish, a solid choice for the majority of applications. But when projects call for added functionality or customisation, colour can be easily introduced through a simple, non-toxic dyeing process, providing a durable, professional finish in a wide range of shades. Whilst Black remains a popular choice, parts can be dyed a range of colours.

Colour can transform not just the appearance, but also the functionality of a part, from customisation, safety, branding and end-use production.

Set of identical grey SLS parts dyed in a range of colours.

Why Dye SLS Parts?

Selective Laser Sintering (SLS) is known for producing durable, functional Nylon parts straight from the printer. While the natural finish is white or grey, dyeing opens up a wider world of applications, without compromising the integrity or performance of the part.

1. Increase Functionality : Colour-coded parts make it easier to identify tools, parts, or stages in a workflow, particularly useful in busy factory or lab environments.

2. Enhance Aesthetics : Add branding or customisation without painting or coating. Ideal for orthotics and prosthetics, product design iteration and prototyping.

Dyeing in Practice

We used the Dyeformer system to dye the PA12 parts. The system has pre-programmed dyeing temperatures and times for both SLS and SLA/Resin parts and uses non-toxic dyes.

Check out the video showing the process involved.

The dyeing process took approximately 1 hour. Drying time varied depending on the method used—2 hours without compressed air, or just 1 hour with the aid of compressed air, such as an air gun.

Our top tips:

• Maintaining consistent dye circulation is essential for achieving even colour distribution. The Dyeformer supports this by actively circulating the dye solution around the part during the dyeing process, helping prevent uneven staining or blotching
• Rinsing the dyed parts in clean water immediately after dyeing helps to remove any excess dye and prevents defects like colour concentration spots
• For optimal drying, it's best to reposition the part periodically to avoid marks or uneven colour caused by stagnant moisture. Using compressed air reduces drying time and ensures a more uniform finish by removing water trapped in crevices or fine details

The dyeing process is straightforward and compatible with common Nylon-based SLS materials. Once dyed, the parts retained their mechanical strength and surface detail.

Unlike surface-level painting, dyeing penetrates deep into the part, ensuring the colour is absorbed throughout the material. This means the finish is durable, won’t chip or wear off, and is ready for real-world use.

We cut this dyed black bracket in half to show the deep penetration of the dye.

Practical Uses of Dyed SLS Nylon 3D Printed Parts

What can you do with dyed SLS parts? A lot. Here are just a few real-world scenarios where colour adds value:

1. Factory Floor Safety and Process Visual Management
Colour-coded tools and jigs improve workflow and reduce the risk of human error. Yellow parts might flag caution areas or red for danger zones. You can have Go/No-Go gauges in red and green. Or colour-coordinate parts based on their prototype stage.

2. End-Use Production at Low Volumes
Not every product justifies the cost of tooling or injection moulding. Dyeing allows you to manufacture short-run batches with a finished look and feel, without compromising lead times or flexibility.

3. Orthotics and Medical Applications
Personalised colours can make orthotics more appealing for patients, particularly children or those who want a discreet or stylish look. Colour can also help practitioners quickly identify sizes or side-specific parts (e.g. left/right foot orthotics).

Colour unlocks new levels of functionality, appeal and usability for SLS 3D printed parts. With straightforward post-processing and no impact on part performance, dyeing makes it easy to go from prototype to polished end-use product.

Whether you’re streamlining your production workflow, improving safety, or delivering customised solutions, dyed SLS parts help you get more from your prints.