Do my files get uploaded?

No. Everything runs in your browser. The file never leaves your computer, so it works for client files and unreleased designs too.

No, and it isn't made by the HueForge team. HueForge is a paid desktop app with a big filament library and more controls. This is a free browser tool for the same basic idea: photo in, STL and swap layers out.

What printer do I need?

Any printer with one nozzle. At each change the printer pauses (or you stop it), you swap the spool, and it carries on. With an AMS or MMU the swaps happen on their own.

Transmission distance: how thick a filament has to be before you can't see through it. Dark filament is low, around 0.5 mm. White is high, 2–5 mm. Higher TD means the colours below show through more.

How do I add the filament changes?

Slice the STL, then move the layer slider to each layer on the swap list. In Bambu Studio and OrcaSlicer, click the + by the slider (or right-click) and add a colour change. In PrusaSlicer it's the + next to the slider. In Cura use Extensions → Post Processing → Modify G-Code → Filament Change.

Is it the same as a colour lithophane?

Close, but not the same. A filament painting is meant to hang on a wall with light in front of it. Hold it up to a window and the colours change, because then you see all the layers at once.

All tools / Filament painting

Free HueForge alternative

Turn a photo into a filament painting: one flat print where thin layers of different filament blend into shades. Pick the spools you own and get the STL plus the layers to swap at.

Good to know

How a filament painting works

It's one flat print, made on a normal printer with one nozzle. You start with a dark filament and swap to lighter ones at set layers as the print goes up.

Thin plastic lets the colour underneath show through. Two layers of white over black look dark grey; ten layers look almost white. So every height prints as a different shade, and the photo's light parts become the tall parts.

This page works out the shade at every layer for the filaments you pick, sets each point of the photo to the closest one, and chooses the swap layers that get the whole picture closest.

Print settings that work

Setting	Start with	Why
Layer height	0.08 mm	Thinner layers give more shades between each colour
First layer	0.16 mm	Sticks well and is easy to match in any slicer
Infill	100%	Gaps inside would show up as marks in the picture
Orientation	Flat, picture side up	The way the file comes out; don't turn it
Ironing	Off	Ironing smears the top layers, and those are the picture

Layer height and first layer must match what you set on this page. If they don't, every swap lands on the wrong layer.

Adding the filament changes in your slicer

Bambu Studio and OrcaSlicer: slice, drag the layer slider to the layer on your swap list, then click the + next to the slider (or right-click it) and add a colour change.
PrusaSlicer: slice, move the vertical slider to the layer, and click the + icon beside it. That adds a colour change (M600) at that layer.
Cura: Extensions → Post Processing → Modify G-Code → Add a script → Filament Change. Add one per swap and type the layer number.
Then scroll the preview through each change. The new colour should start on the layer from the list.

Picking filaments

Put your darkest filament at the bottom. It's the base, and it's the colour of the deepest shadows.
Three or four filaments are plenty. Black, grey and white already gives a good black-and-white picture.
Use the same type of filament (all PLA, say) so the layers bond and print at one temperature.
Not sure of a spool's TD? Print a small step test (a strip that gets 0.08 mm thicker each step) over black, and see at which step you can no longer see the black. That thickness is the TD.
Try "Colours picked from my photo" to see which colours the photo wants, then pick the spools you own that come closest.

This page or HueForge?

	This page	HueForge
Price	Free	Paid licence
Runs in	Your browser, nothing to install	A desktop app you install
Filament list	You type in colour and TD	A large library of measured filaments
Control	Filaments, heights and swap layers	Many more settings and tools

If you print these a lot and want fine control, HueForge is worth a look. For trying the idea, or a quick print from a photo, this page does the job.

How it works

1Drop a photo. Pick the filaments you own, darkest at the bottom.
2Check the preview. We place the filament changes for you; move them if you like.
3Download the STL and the swap list. Add the changes in your slicer and print it flat.

Questions people ask

Checked October 2026

Do my files get uploaded?: No. Everything runs in your browser. The file never leaves your computer, so it works for client files and unreleased designs too.
Is this HueForge?: No, and it isn't made by the HueForge team. HueForge is a paid desktop app with a big filament library and more controls. This is a free browser tool for the same basic idea: photo in, STL and swap layers out.
What printer do I need?: Any printer with one nozzle. At each change the printer pauses (or you stop it), you swap the spool, and it carries on. With an AMS or MMU the swaps happen on their own.
What is TD?: Transmission distance: how thick a filament has to be before you can't see through it. Dark filament is low, around 0.5 mm. White is high, 2–5 mm. Higher TD means the colours below show through more.
How do I add the filament changes?: Slice the STL, then move the layer slider to each layer on the swap list. In Bambu Studio and OrcaSlicer, click the + by the slider (or right-click) and add a colour change. In PrusaSlicer it's the + next to the slider. In Cura use Extensions → Post Processing → Modify G-Code → Filament Change.
Is it the same as a colour lithophane?: Close, but not the same. A filament painting is meant to hang on a wall with light in front of it. Hold it up to a window and the colours change, because then you see all the layers at once.