Multicolor name keychain
without an AMS
You don't need an AMS for a two-colour name keychain. Print the plate in one colour, pause at the layer where the letters start, swap the spool by hand and resume. On a NameSTL keychain at default settings that layer sits at 2.5 mm.
By Philipp Baldauf · Updated September 29, 2026
The short answer
A filament change at one layer is all it takes. Everything below that layer prints in colour one (plate and ring), everything above it in colour two (the name). Any printer that can pause can do this: an A1 mini without AMS, a P1S, a Prusa MK4, an Ender 3.
The layer you want is the first one that contains only letters. Take the height where the plate ends and divide it by your layer height. On a keychain from the name keychain generator with a letter thickness of 5 mm or less, the plate ends at 2.5 mm: the 2 mm plate plus 0.5 mm that the plate reaches up into the letters so both fuse into one solid. At 0.12 mm layers that's layer 21, at 0.2 mm layer 13 or 14. The table further down has the numbers for thicker settings.
Design the keychain first
Set the text colour and the plate colour to the two filaments you own. What you see is what the printer will make.
Why this design swaps cleanly
Some keychain files embed the letters in the plate or give them a bevel that starts below the plate surface. Then no single height separates the colours and you're stuck with an AMS or a paint pen. Our keychains are built the other way round: a flat plate at the bottom, the letters standing fully on top of it. Every layer below the plate top is plate only, every layer above it is letters only. One swap gives you a clean edge.
The 3MF export goes one step further. Letters and plate are separate parts on separate filament slots, so in Bambu Studio or OrcaSlicer you can see exactly where one ends and the other begins. The ring hole is part of the plate, so it takes the plate colour. If you only print in one colour, the STL works just as well; the layer trick is the same.
Designing and previewing is free and needs no account. You pay when you download: $4.99 for a single file for personal use, or Unlimited from $9.99 a month if you print keychains to sell (see pricing).
Which layer to change at
Plate depth in the generator is 40% of the letter thickness, never less than 2 mm. The plate top sits 0.5 mm higher, where the plate reaches into the letters. Values are for the model at 100% height with a 0.2 mm first layer, which is the default in Bambu Studio, OrcaSlicer, PrusaSlicer and Cura.
| Thickness setting | Plate top (change height) | Total height | 0.2 mm layers: first letter layer | 0.12 mm layers: first letter layer |
|---|---|---|---|---|
| 0.5 to 5 mm | 2.5 mm | 2.5 to 7 mm | 13 or 14 | 21 (Z 2.60) |
| 6 mm | 2.9 mm | 8.4 mm | 15 or 16 | 24 or 25 |
| 7 mm | 3.3 mm | 9.8 mm | 17 or 18 | 28 (Z 3.44) |
| 8 mm | 3.7 mm | 11.2 mm | 19 or 20 | 31 (Z 3.80) |
| 10 mm | 4.5 mm | 14 mm | 23 or 24 | 38 (Z 4.64) |
Where two numbers are given, the plate top falls exactly in the middle of a layer and the slicer rounds it one way or the other. Always check the preview: the right layer is the first one that shows only letters. If you scale the model's height in the slicer, the change height scales with it (2.5 mm at 60% becomes 1.5 mm). Scale only X and Y and the numbers above stay valid.
Bambu Studio, step by step
For an A1, A1 mini, P1 or X1 printing from the external spool.
- 1
Open the 3MF and put both parts on one filament
The file opens with the plate on filament 1 and the letters on filament 2. Without an AMS, set both parts to filament 1 so the printer doesn't expect an automatic change. Or open the STL, which arrives as a single part.
- 2
Scale only the width if you need a smaller tag
Untick uniform scaling and change X and Y. The height stays at 100%, so the layer numbers in the table still apply. See the keychain size guide for good lengths.
- 3
Slice and find the first letter layer
In the preview, drag the vertical layer slider up until the plate disappears and only letters remain. At 0.12 mm and default thickness that's layer 21 at Z 2.60.
- 4
Add the pause
Right-click the plus icon next to the slider on that layer and choose Add Pause. A small marker appears on the slider.
- 5
Swap the spool when it stops
The printer parks and waits. On the screen, unload the filament, load the second colour and let it extrude until the colour runs clean. Pull the blob off the nozzle with tweezers, then resume.
OrcaSlicer
Same idea as Bambu Studio, with more printer types.
- 1
Slice and move the slider
Open the 3MF or STL, slice, and drag the layer slider to the first layer that shows only letters.
- 2
Pick pause or colour change
Right-click the plus icon. On Bambu printers choose Add Pause. On Marlin printers with M600 enabled, Add Color Change is nicer because the printer unloads and asks for the new filament by itself.
- 3
Check the machine G-code on Klipper
Klipper has no M600 out of the box. Either add an M600 macro, or use Add Pause and make sure Printer settings, Machine G-code, Pause G-code contains PAUSE.
PrusaSlicer
- 1
Slice and open the preview
Import the STL or 3MF. If PrusaSlicer shows the 3MF as two objects on a single-extruder printer, that's fine: both print with the same extruder.
- 2
Add the colour change
Move the vertical slider to the first letters-only layer and click the orange plus icon. That inserts an M600 colour change. Right-click it instead for Add pause print (M601).
- 3
Follow the printer's prompts
A Prusa MK4, MK3S or MINI unloads the filament, beeps, and asks you to load the new one. It purges and asks whether the colour is clean. Answer no until it is.
Cura
- 1
Find the layer number
Slice, switch to Preview and move the layer slider until only letters are left. Note the layer number Cura shows.
- 2
Add the post-processing script
Go to Extensions, Post Processing, Modify G-Code, Add a script, and pick Pause at height. Set Pause at to Layer Number and enter the layer from step 1. If your firmware supports M600, the Filament Change script does the unload for you.
- 3
Check the numbering once
The script's layer counting has changed between Cura versions, so read its tooltip. On the first print, watch where it stops. If it pauses one layer too early you'll see a thin letter-coloured skin on the plate; move the pause up by one.
What AMS users do instead
If you do have an AMS, AMS lite or an MMU, there's nothing to set up.
Open the 3MF and print
Bambu Studio and OrcaSlicer open the file with two colours already assigned. Map the two slots to the right spools and send it.
Barely any purge
Because the colours sit at separate heights, the AMS swaps once or twice per plate, not every layer. A full plate of ten keychains still wastes only one or two purges.
More than two colours
With an AMS you can paint single letters or the letter tops in a third colour in Bambu Studio. That's the one thing the manual swap can't do.
Methods compared
| Method | Colours | Your work | Waste | Good for |
|---|---|---|---|---|
| Pause at height, manual swap | 2 (a third as a band on the letter tops) | 1 to 2 minutes per swap | a short purge by hand | any single-nozzle printer |
| AMS, AMS lite, MMU | up to 4 or more | none | a flush per swap, small here | batches, per-letter colours |
| Print once, paint the letters | any | 10 to 20 minutes with a paint pen | none | a one-off, or a printer that can't pause |
| Two prints, glued | any | gluing and alignment | none | letters that must be a different material |
The limits, honestly
A manual swap changes the colour of a whole layer. You get colours in bands by height, not side by side. For this keychain that means plate plus letters, two colours. You can add a second swap near the top so the letter faces come out in a third colour, but different colours for single letters need an AMS or paint.
Expect a little colour bleed. The first millimetre of new filament carries old colour from the nozzle. Going from a dark plate to white letters shows it most, as a grey foot at the base of the letters. Purge 50 to 100 mm of the new filament before you resume and the band disappears. The swap also means you have to be at the printer when the pause comes, which on a keychain at 0.12 mm is roughly 10 to 15 minutes after the start.
Fixes for the usual problems
- The plate top came out in the letter colour: the pause was one layer too early. Move it up by one.
- A thin plate-coloured band at the foot of each letter: the pause was one layer late. It's often hard to see; move it down by one if it bothers you.
- A blob or string on the first letter after resuming: wipe the nozzle before you resume and don't let it sit hot with filament oozing.
- Letters don't stick to the plate after a long pause: PLA copes with 10 minutes, but a long wait lets the plate cool and shrink. Keep the bed heated and swap promptly.
- The printer doesn't stop at all: in Cura the script wasn't active when you saved, and on Klipper the pause macro is missing. For more slicer basics see keychain slicer settings.
Questions people ask
How do you multi color 3D print without an AMS?
Add a pause or a filament change in your slicer at the layer where the second colour starts. When the printer stops, unload the first filament, load the second, purge until it runs clean and resume. It works on any printer that can pause, and for a name keychain one swap is enough.
At which layer do I change filament on a name keychain?
At the first layer that contains only letters. For a NameSTL keychain with 5 mm or less letter thickness the plate ends at 2.5 mm, which is layer 21 at 0.12 mm or layer 13 to 14 at 0.2 mm. Check the preview, because slicers round a layer that falls exactly on the boundary differently.
Can I use the 3MF on a printer without an AMS?
Yes. Assign both parts to the same filament in Bambu Studio or OrcaSlicer, then add a pause at the letter layer. Or open the STL instead, which is one part and slices the same way.
How many colours can I get with filament changes?
One per height band. On a keychain that's the plate and the letters, and with a second pause near the top you can give the letter faces a third colour. Colours that sit next to each other in the same layer, like one red letter and one blue, need an AMS or MMU.
Does a filament change weaken the keychain?
Not noticeably if you swap within a few minutes and keep the bed hot. The layers bond the same as any other layer. After a very long pause the plate cools, and the first letter layer may bond a bit worse.
Why does my second colour look muddy?
That's colour bleed from filament left in the nozzle. Push 50 to 100 mm of the new colour through before you resume, more when you go from dark to light. Picking the darker colour for the letters hides it best.