How to Color Models in QIDI Studio?

To colour a model in QIDI Studio, open the project, add one filament slot per colour in the left-hand filament list, then open the Colour Painting tool and paint the model with one of six brushes — Circle, Sphere, Triangle, Height Range, Fill and Gap Fill. Slice, sync the filament list from your QIDI BOX, and the printer changes colour on its own.

I print a lot of small character models, and the part that used to scare me off multi-colour was not the hardware — it was the painting. It looks like a graphics program. It is not. There are six brushes, each one selects triangles a different way, and once you know which brush selects what, a model like the penguin below takes about ten minutes to paint.

What colour painting in QIDI Studio actually is

Colour painting is filament assignment, not texturing. When you paint a face, you are not applying a colour to a surface — you are telling the slicer which filament slot should extrude that region. That is why the palette in the painting toolbar is exactly as long as your filament list, and why adding a seventh colour means adding a seventh filament, not picking a seventh swatch.

It also explains the one limit that catches new users: a face is either one filament or another. There is no blending inside a single layer, so gradients are built from bands of solid colour, not from mixing.

You need QIDI Studio for this workflow. Painting data is stored in the project file, so save as 3MF if you want to keep it — exporting to STL throws every paint stroke away.

The six colour painting tools, and when to reach for each

The order I use almost every time: Circle to draw boundaries → Fill for the big areas → Height Range for anything banded → Gap Fill last. Sphere and Triangle are repair tools, not primary brushes.

What you need on the hardware side

Painting is free — every QIDI Studio install has it. Printing what you painted needs a way to change filament. A QIDI BOX holds four spools and swaps them automatically, and up to four boxes chain together for sixteen filaments in one job. Full wiring and first-run setup is covered in the multi-colour setup tutorial, and the box's drying and sensing features are broken down in the QIDI BOX guide.

Without a box you can still use painting — assign colours by height with the Height Range tool, then pause and swap the spool by hand at each transition. It works, it just needs you in the room.

Sketch Map

Multi-color printed model:

If you want to achieve similar results, follow the steps below.

Step by step: painting the penguin

1. Add one filament per colour

Open the model file. In the filament panel on the left, click the "+" to add a slot, then set the type and colour for each one. Pick the real filament colours you actually own — the swatch you choose here is what you will be matching to a physical spool later, and guessing at this stage means repainting. You can also add or remove slots from the toolbar at the top while the painting tool is open.

Keep all colours in one material family. Mixing PLA and PETG in one print means one of them is running at the wrong temperature at every changeover.

2. Draw the boundaries first

Select the filament you want to paint with, then pick a tool. The white and black regions of this penguin meet on a smooth curve with no crease for the Fill tool to stop at, so I use the Circle brush first to draw the dividing line by hand. Drop the brush size to roughly 1 mm for the boundary pass — a fat brush gives you a wobbly edge you will spend longer fixing than drawing.

3. Fill the large areas

Switch to the Fill tool and click inside each region you just enclosed. If the fill jumps the boundary, the boundary has a gap — undo, thicken that stretch with the Circle brush and click again. This is the step where a careful boundary pass pays for itself.

4. Use Height Range for the hat

Anything that is genuinely a band — a hat brim, a stripe, a base — is faster with Height Range. Set the lower and upper Z values before you click, and remember the range is measured from the build plate, not from the bottom of the part, so a model lifted on a raft shifts every number.

5. Clean up with Gap Fill

Use Gap Fill to catch the small unpainted specks a fill always leaves behind. Nudge the gap area value up a step at a time and watch the preview — push it too far and it will happily erase a deliberate detail along with the noise.

6. Sync the box, then print

Load the spools into the multi-colour box, then click the sync button to pull the box's filament list into the project. In matching mode QIDI Studio maps each painted colour to the slot that physically holds it — check the mapping before you confirm, because a wrong slot is not a defect you can sand out. Then transfer and print.

The settings that decide how clean the colours look

Painting sets where the colours go. These settings decide whether the boundaries come out crisp or muddy.

Colour changes cost filament and time. A model with a change on nearly every layer can spend more material on purging than on the part, which is the usual reason a "quick" multi-colour keychain turns into a six-hour job.

Three things I got wrong so you do not have to

• I exported to STL and lost everything. Paint data lives in the 3MF project. Save the project, then export.
• I painted before scaling. Height Range values are absolute, so scaling the model afterwards moves every band. Scale first, paint second.
• I trusted the on-screen swatch. Screen colour and filament colour are not the same thing, especially with translucent and silk filaments. Print a small colour swatch once and keep it on the bench.

FAQ

How many colours can QIDI Studio print in one model?

One QIDI BOX holds four filaments, and up to four boxes can be chained for sixteen filaments in a single job. QIDI Studio lets you add filament slots up to the number your hardware can feed.

Can I do multi-colour printing without a QIDI BOX?

Yes, with manual spool swaps. Assign the colours with the Height Range tool so every change happens at a clean Z height, then pause the print at those heights and change the spool by hand. It is fine for two or three bands and painful beyond that.

Why does my colour boundary look blurred or smeared?

That is residual filament from the previous colour, not a painting error. Increase the flushing volume for that specific colour pair, especially when a dark colour is followed by a light one, and keep the prime tower enabled.

Does painting a model change how long it takes to print?

Yes. Every colour change adds a purge and a tool change, so print time and filament use both rise with the number of transitions, not with the number of colours. Two colours that alternate on every layer cost far more than four colours in four separate bands.

Is QIDI Studio free, and is it the same as Orca Slicer?

QIDI Studio is free and open source under AGPL v3. It is not a version of Orca Slicer — both projects forked separately from Bambu Studio, so they are siblings rather than one being built on the other. You can read QIDI Studio's source in the QIDI Studio repository and Orca Slicer's in the Orca Slicer repository. Only QIDI Studio talks to the QIDI BOX.

Conclusion

Six brushes, one sensible order, and a flushing setting that matches your colour pairs — that is the whole of multi-colour painting in QIDI Studio. Once the workflow is muscle memory, the same tools handle embossed text and colour-coded assemblies just as easily. Reference material for the software lives on the QIDI wiki, and every current machine in the QIDI printer range runs the same painting workflow. What multi-colour models have you printed? Share your multi-colour projects in the comments.