How to Add Color to Your Bookmark in Bambu Studio

Here's the one thing to know up front: your bookmark download is geometry, not color. ButterySpace hands you a clean, two-sided bookmark shape. It does not assign, bake in, or auto-load any colors, and nothing pops up pre-painted when you open the file. That's deliberate. Color should be your choice, made with the filaments you actually own. The good news: adding it in Bambu Studio takes about a minute. This guide covers the two methods makers reach for most.

Before you start

• Open bookmark.3mf (or the STL) in Bambu Studio. It loads as a single object.
• Make sure you have more than one filament available. Region painting is best with an AMS or another multi-material setup; on a single-extruder setup, simple height-based color changes are usually the practical path.
• Add the filament colors you want to use to the filament list at the top of the window, so they're ready to assign.

Method 1: the Color Painting brush (best for design vs. background)

This is the most flexible method. It lets you paint specific regions of the bookmark, for example the raised design in one color and the base in another.

1. Select the bookmark, then open Color Painting from the left-hand toolbar (the paint-brush icon).
2. Choose the filament color you want to apply from the row of color chips that appears.
3. Pick a tool:
   • Smart fill is the fastest for a relief bookmark: click a face and it fills the connected area up to the angle threshold, so one click often colors the whole raised design or the whole flat base.
   • Brush / Bucket give you finer manual control for individual areas.
   • Gap fill and the brush-size slider help you clean up edges.
4. Click the parts you want in each color, switching the active filament chip as you go.
5. Rotate the model and check the back. On a two-sided bookmark you can color each face independently.
6. When it looks right, slice. With an AMS or another multi-material setup, Bambu Studio assigns the painted regions to the selected filaments. Without AMS, expect manual swaps or keep the paint plan very simple.

Method 2: a color change by height (best for a clean base/top split)

If you want the bookmark to be one color up to a certain height and a second color above it (a colored base with a contrasting raised image, say), a height-based color change is simpler than painting.

1. Slice the bookmark first so you can see the layer preview.
2. Switch to Preview and use the vertical layer slider on the right.
3. Drag the slider to the layer where you want the color to switch (usually where the raised design begins).
4. Click the + on the slider and choose Add color change (or assign the next filament at that height).
5. Re-slice. Everything below the line prints in the first color; everything above prints in the second.

Quick tips for clean results

• Higher contrast reads better. A bookmark is small; two colors that are clearly different will show the design far better than two close shades.
• Use Smart fill first, clean up second. Let Smart fill do the bulk of the work, then touch up stray faces with a small brush.
• Check both sides. The bookmark is two-sided, so rotate the model and don't leave the back unpainted by accident.
• Save your work as a project. Save the Bambu Studio .3mf project after painting so your color setup is preserved for next time. (That saved project is yours, separate from the geometry-only file ButterySpace gave you.)

Why we don't pre-color the file

It would be easy to ship a 3MF with colors already assigned, but it would also be wrong for most people. We don't know which filaments you own, which printer you're on, or whether you even want two colors. Pre-baked color assignments tend to fight your actual setup and get deleted anyway. Handing you clean geometry and a one-minute coloring step puts you in control and works on every slicer, not just one.