Finishing · Black Dyeing · UK

Black Dyeing for 3D Printed Nylon

A uniform, deep black finish on SLS and MJF nylon parts — without adding a single micron of wall thickness. Dyeing colours the part itself rather than coating it, so tight-fitting assemblies, threads and snap features go together exactly as they came off the machine. Done in-house at our ISO 9001 facility, on runs from one part to 100,000.

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Before and after

The same part, as printed and dyed

One MJF nylon vent component, photographed before and after dyeing. Nothing else about the part has changed — same tooling-free build, same geometry, same dimensions.

As-printed MJF PA 12 nylon vent components 3D printed by RYSE 3D in their natural grey finish before black dyeing — As printedMJF PA 12 straight from the machine, shot blasted. The natural grey of the fusing agent, with the matte powder-bed texture visible across the louvres.

The same MJF PA 12 nylon vent components after black dyeing by RYSE 3D, showing uniform deep black colour with unchanged dimensions — Black dyedThe same components after dyeing. Deep, even black into every louvre slot and internal face — places a spray gun could not reach without building up thickness.

Look at the louvre slots in particular. Dye reaches into narrow internal geometry at the same strength as the outer surface, because the part is immersed rather than sprayed. That is the practical difference between colouring a part and coating one.

Overview

What black dyeing does to a 3D printed part

Powder-bed nylon comes off the machine porous. That porosity is usually something we work around — in dyeing it is the whole point. The part is immersed in a heated black dye bath and the dye is drawn into the surface layer of the polymer, colouring the material rather than sitting on top of it. There is no film, no build-up and no edge to chip.

The practical consequence is dimensional. A coat of paint is a physical layer with a thickness that has to be accounted for on every mating face, every thread and every clearance. Dye is not. A dyed bracket assembles to the same drawing as an undyed one, which is why dyeing is the default cosmetic route for functional nylon parts that still have to fit something.

It is also the cheapest way to make a batch look like it belongs together. SLS PA12 leaves the machine an off-white that varies subtly across a bed and between builds; dyeing takes the whole batch to a consistent black regardless of where each part was nested.

Reviewed by the RYSE 3D engineering team · August 2026.

At a glance	Detail
Processes	SLS and MJF only — powder-bed nylon
Colour	Black
Added thickness	None — no measurable dimensional change
Penetration	Surface layer only — not through-colour
Mechanical effect	No change to part strength or stiffness
Internal geometry	Reached — parts are immersed, not sprayed
Typical pairing	After shot blasting, before assembly
Batch size	One part to 100,000 — priced on the instant quote
Lead time	Adds to the standard process lead time — confirmed at quote

Why dye

Why choose black dyeing

Six reasons it is the default finish on functional nylon parts.

No dimensional penalty

Nothing is added to the surface, so clearances, threads, bores and snap fits stay exactly as designed. This is the single reason dyeing beats painting on assembled parts.

Nothing to chip or flake

There is no coating layer, so there is no adhesion failure mode. Handling marks, scuffs and edge wear do not produce the bright chips a painted nylon part shows.

Reaches internal geometry

Immersion colours ducts, louvres, undercuts and internal channels as evenly as the outside. Spraying cannot reach them, and would add thickness where it did.

Batch consistency

Raw SLS nylon varies in shade across a bed and between builds. Dyeing lands the whole batch on one colour, which matters when parts sit next to each other in an assembly.

Cheap at volume

Parts are dyed together in batches rather than one at a time, so unit cost drops sharply as quantity rises — unlike painting, which is largely per-part labour whatever the run size.

Mechanically neutral

Dyeing does not change the strength or stiffness of the part. The property data on the material page still applies to a dyed component.

Materials

Which 3D printing materials can be dyed black

Dyeing needs porous, powder-bed nylon. That rules a lot in and some things out.

Material	Process	Dyes?	Notes
PA12	SLS	Yes — best result	Unfilled nylon, off-white as printed. The benchmark case for dyeing.
PA11	SLS	Yes	Bio-based nylon, takes dye comparably to PA12.
PA12-GF	SLS	Yes, with a caveat	Glass content does not take dye, so the finish reads slightly less deep than unfilled nylon.
PA 12	MJF	Yes	Already dark grey from the fusing agent — dyeing takes it to a uniform deep black, as shown above.
PA 11 Gen2	MJF	Yes	As MJF PA 12, with the higher impact toughness of PA 11.
PA12-CF	SLS	Not needed	Already black from the carbon loading. Dyeing adds nothing.
FDM grades	FDM	No	Extruded filament is not porous. Colour comes from the raw material, or from painting.
SLA resins	SLA	No	Cured resin will not absorb dye. Choose a black resin such as Black PU, or paint.

Dyeing is normally the last step before assembly. Parts are typically shot blasted first to give an even surface for the dye to take to, and threaded inserts go in afterwards. See the full finishing services range.

Honest limits

Where black dyeing is the wrong call

Dyeing is cheap, dimensionally neutral and looks good. It is not a coating, and there are jobs it cannot do.

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It is not through-colour

Dye penetrates the surface layer, not the full wall. Machine, drill or deeply abrade a dyed part after the fact and you will expose lighter material underneath. If a face is going to be cut, cut it first and dye afterwards.

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Prolonged UV exposure

Dyed nylon is not a UV-stable exterior finish and will lighten over sustained sunlight exposure. For outdoor parts that have to hold their colour, painting with a UV-stable topcoat is the right route, or an inherently UV-stable grade such as ASA.

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Any colour other than black

We run black. If you need a specific brand colour, a RAL or Pantone match, or a gloss level, that is a painting job — dye cannot hit a colour reference.

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Sealing a porous part

Dyeing colours the porosity, it does not close it. A dyed part is no more airtight or watertight than an undyed one. For fluid-tight nylon, vapour smoothing is the process that seals the surface.

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A gloss or A-class surface

Dyeing does not change surface texture — a matte powder-bed part stays matte, just black. For a smooth or glossy cosmetic surface, pair with vibro polishing or go to A-class painting.

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High-abrasion wear faces

On a sliding or rubbing face, the dyed surface layer will eventually wear through to lighter material. Cosmetically critical wear surfaces are better served by a black-through material such as PA12-CF.

Comparison

Black dyeing vs painting vs vapour smoothing

The three routes to a better-looking nylon part, and what each one actually changes.

	Black dyeing	Painting	Vapour smoothing
Changes colour	Yes — black only	Yes — any colour	No
Adds wall thickness	No	Yes	No
Reaches internal geometry	Yes	No	Yes
Changes surface texture	No	Yes	Yes — smooths
Seals porosity	No	Partly	Yes
Can chip	No	Yes	No
Cost at volume	Lowest	Highest	Low
Read more	This page	Painting & A-class	Vapour smoothing

These are not mutually exclusive. A common production route is shot blast, vapour smooth, then dye — sealed, smoothed and black, with no dimensional change from any of the three.

FAQ

Black dyeing FAQ

What is black dyeing for 3D printed parts?

Black dyeing is a finishing process for powder-bed nylon parts. The part is immersed in a heated black dye bath and the dye is absorbed into the porous surface of the polymer, colouring the material rather than coating it. Because nothing is added to the surface, the part keeps its printed dimensions exactly. At RYSE 3D it is available on SLS and MJF nylon parts and is done in-house at our ISO 9001 facility in Shipston-on-Stour.

Which 3D printing materials can be dyed black?

Powder-bed nylons: SLS PA12, SLS PA11, SLS PA12-GF, MJF PA 12 and MJF PA 11 Gen2. SLS PA12-CF is already black from its carbon loading so does not need dyeing. FDM and SLA parts cannot be dyed at all, because extruded filament and cured resin are not porous enough to absorb dye. For those, colour comes from the raw material or from painting.

Is the black colour all the way through the part?

No. Dye penetrates the surface layer of the part, not the full wall thickness. For almost every application this is irrelevant, but it matters in two cases: if you machine or drill a dyed part afterwards you will expose lighter material at the cut, and on a high-abrasion sliding face the dyed layer can eventually wear through. Where through-colour genuinely matters, SLS PA12-CF is black throughout.

Does dye reach inside ducts and internal features?

Yes. Parts are immersed in the dye bath rather than sprayed, so internal channels, louvre slots, undercuts and blind pockets colour as evenly as the outer surface. This is a real advantage over painting on parts like ducting and vents, where a spray gun cannot reach the internal faces and would add wall thickness anywhere it did.

Will dyed 3D printed parts fade in sunlight?

Over sustained UV exposure, yes. Dyed nylon is not an exterior-grade colour finish and will lighten over time outdoors. For parts that live outside and have to hold their colour, painting with a UV-stable topcoat is the correct route, or choosing an inherently UV-stable material such as ASA. Indoors, or for enclosed and under-bonnet parts, dyeing holds its colour without issue.

Black dyeing or painting — which should I choose?

Choose dyeing if the part has to fit something, if it has internal geometry that needs colouring, if it will be handled a lot, or if you are running volume — it adds no wall thickness, cannot chip, and gets cheaper per part as the batch grows. Choose painting if you need a specific colour reference, a gloss level, an A-class cosmetic surface, or UV durability outdoors. On assembled products the two are often combined: dyed internal components, painted visible panels.

How do I order black dyed 3D printed parts in the UK?

Upload a STEP or STL to our instant quote tool, choose an SLS or MJF nylon and select dyeing as the finish, and you will get GBP pricing in seconds on anything from one part to 100,000. Dyeing adds to the standard process lead time and your exact date is confirmed at quote. If you would rather see the finish first, request a free sample pack, or call our engineers on 024 7736 0144.

Ready when you are

Send the CAD. Get it back in black.

Upload your part, pick an SLS or MJF nylon and add dyeing as the finish. Printed, dyed and inspected under one roof in the UK.

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Our own ISO 9001 facility in Shipston-on-Stour, Warwickshire. Mon–Thurs 8am–4pm, Fri 8am–2pm, visits by appointment. Call 024 7736 0144 or email hello@ryse3d.com.