Most 3D printers have one nozzle and therefore one material at a time. If you want a nameplate with a black background and gold lettering, the usual way is to print two parts and put them together. Our Bambu Lab X2D has two nozzles — and this opens up a third way: the two colours in the same layer, as a single part.
What the two nozzles actually do
The two nozzles do not print at the same time. The printer moves one nozzle and the other waits on the side; when the layer reaches an area with the other colour, the heads are mechanically swapped and the second continues. Within a layer this can happen many times.
The result is a part where the colour border runs through the material rather than a glued joint. The built-in inscription cannot fall off - it is part of the object: there is no joint to peel off like a sticker, and as the surface wears, the two materials wear together.
When is it the right choice
- Inscription or logo on a surface — nameplates, company signs, gifts. The most common case.
- Pattern or field in another colour — areas of the upper surface that should contrast.
- Functional designation — arrow, scale, number that must not rub off.
And when it's not: if the coloured parts of the model are separate parts, it's cheaper to print each one in its own colour and put them together - it doesn't make printing more expensive at all. And if you only need a change of colour in height (light body, dark base), it is also the simpler and cheaper arrangement. Both paths are described on the "Materials" page.
Why it costs more
Changing the colour in the layer is not free for the machine, for three reasons:
- Purging. At each change, the nozzle must extrude some material so that one colour does not contaminate the other. This material goes in the bin - with many changes, it is by no means small.
- Time. Swapping heads and purging takes seconds, but repeats itself over and over, layer after layer. Two-colour printing of the same model is noticeably slower.
- Failed prints. Two-colour prints are more demanding: a dark smudge on the light colour is immediately visible and may require the print to be repeated.
Therefore, in the calculator, the "Second colour in one layer" checkbox adds 25% to the print price. The number isn't rounded up "just in case" — it covers scrap, extra time, and a higher proportion of reprints.
How to order it
Upload the model to the Upload model page, select a material and check "Second colour in one layer" - it appears for PLA and Polycarbonate where we are sure of the result. You choose the second colour from the list, and in the note to the order you describe which colour each part of the model should be. If in doubt, we will ask you by email before we start printing.
One limitation is good to know in advance: with two-colour printing, the build volume is slightly narrower — 235 × 256 × 256 mm instead of the full 256 × 256 × 260, because both nozzles have to reach the entire part.
What to put in the model
The two-colour pattern must be divided into bodies — one for each colour. If you are modelling yourself:
- Make the inscription a separate body, not engraving on the main one.
- Keep the lettering strokes wider than a millimetre. In our own samples with a company logo, thinner strokes were lost or chipped—the nozzle simply can't draw a line thinner than it is.
- Think about the top or bottom surface of the part: colour graphics look best on a plane, not a steep wall.
If you only have a picture or a logo and not a 3D model — write to us. Preparing a two-colour model from artwork is exactly one of the things we do to your specification.
For more than two colours, for other materials or if you are unsure which of the three methods suits your project — write to us, we evaluate honestly and sometimes the answer is "the cheaper option is enough for you".