3D Print Finishing Options: Picking the Right Coat

Our finishing quote tool offers a short menu of coats, and on first read the names blur together. They fall into three groups: surface prep, 1k automotive paint, and 2k automotive paint. This guide maps each option to what it actually does, so you can pick in a minute and see your quote. For the technique behind every step, our pillar on 3D printing painting and surface finishes goes deeper. This is the shorter “which coat do I pick” version.

First comes the surface, not the colour

Gloved hands wet-sanding a grey primer-coated 3D-printed part to smooth away layer lines

Filling & Sanding is the foundation, and it isn’t a colour. An FDM print comes off the machine with visible layer lines and the odd seam mark. Paint on its own doesn’t hide those lines. It follows them. Filling and sanding levels the ridges and smooths the surface, so every coat after it sits flat and reads like a moulded product instead of a print.

Two identical green 3D-printed vases with the same gloss paint: the left was sprayed over a raw print and shows layer lines telegraphing through the paint, the right was filled and sanded smooth before painting — Same part, same paint, same gloss. Left: sprayed straight onto the raw print, so the layer lines telegraph through. Right: filled and sanded first, then painted.

Most painted parts start here. Want the raw print? Skip it. Want any kind of finished look? This is the step that earns it, and it’s why a properly finished part costs more than a bare one. The pillar guide covers the grits and primer in detail.

1k automotive paint: everyday colour and protection

“1k” means single-component paint. It air-dries, costs less, and gives solid everyday durability. It’s the right call for display pieces, indoor props, and models that live on a shelf or in a cabinet. Three options sit in this group:

Red 3D-printed car model with a 1k base colour coat, satin and unsealed — 1k Automotive Paint

The same red car model under a glossy standard clear coat — Standard Clear Coat

The same red car model under a matte clear coat — Matte Clear Coat

1k Automotive Paint is the colour coat itself. This is where your part gets its actual colour.
Standard Clear Coat seals that colour under a glossy top layer. Gloss looks wet and bright, and it makes metallics and deep colours pop.
Matte Clear Coat does the same sealing job with a flat, glare-free sheen. It suits scale models, architectural pieces, and anything you’d rather keep understated.

Pick the colour coat, then one clear coat in the sheen you want.

2k automotive paint: tougher, for parts that get handled

“2k” means two-component paint, catalysed with a hardener before it’s sprayed. That chemistry cures into a far harder shell. You pay a bit more for a noticeably tougher finish: better scratch resistance, better chemical resistance, and better resistance to UV. Reach for 2k when the part gets handled often, carried around, or kept outdoors in the Singapore sun and humidity, where a softer finish would chalk or fade. The same three choices apply:

Blue 3D-printed helmet with a 2k base colour coat, satin and unsealed — 2k Automotive Paint

The same blue helmet under a glossy 2k clear coat — 2k Standard Clear

The same blue helmet under a matte 2k clear coat — 2k Matte Clear

2k Automotive Paint (scratch resistant) is the hardened colour coat.
2k Standard clear coat is the glossy, catalysed top layer.
2k Matte clear coat is the flat-sheen version of the same.

How to choose

Three quick decisions get you to a spec:

1k or 2k? Durability versus cost. Indoor display and light handling: 1k is plenty. Daily handling, outdoor life, or anything that takes knocks and sun: 2k. Unsure? Tell us how the piece will be used and we’ll steer it.
Gloss or matte clear? Sheen only, and both come in 1k and 2k. Gloss for a wet, vivid look. Matte for a flat, no-glare finish.
Custom colour or a preset? We mix to any colour, so send a Pantone code or a hex value and we match it. If a stock colour works, pick one off the shelf instead. Our colour guide and spray paint colour catalogue show the range.

Get a finishing quote

You don’t have to lock this in before you start. Open the finishing quote tool, choose your coats, and the price for your exact part shows up straight away. Still weighing it up? Pick the closest option, add a note, and our studio will confirm the best spec for how you’ll actually use the piece.

Frequently asked

What's the difference between 1k and 2k clear coat?

1k is single-component paint that air-dries. 2k is mixed with a hardener before spraying, so it cures into a much harder shell. 2k resists scratches, chemicals, and UV far better, which makes it the pick for parts that get handled often or live outdoors. 1k costs less and is fine for indoor display pieces. Both come in gloss (standard) and matte sheens.

Which 3D print finish is the most scratch resistant?

A 2k automotive paint under a 2k clear coat. The catalysed two-component system cures harder than any single-component (1k) finish, so we spec it for trophies that get passed around, functional parts, and anything kept outside in the Singapore weather. For a piece that only sits on a shelf, 1k is usually enough and costs less.

Can you match a specific colour?

Yes. Send a Pantone code or a hex value at quote time and we mix the colour to match, in either 1k or 2k paint. If a stock colour works, you can pick one off the shelf instead. Filament colour isn't reliable for brand-exact work, so we print in a base colour and paint to your target. Our colour guide shows what the range covers.

Do I need filling and sanding before painting?

For FDM prints, almost always. Layer lines and seam marks show straight through paint unless the surface is filled and sanded flat first. It's the foundation step, not a colour, and it's what separates a finished-looking part from one that still reads as printed. Resin (SLA) prints start smoother and need less, but most painted parts include some prep.