This is a remix of 3dprintingworld's Secret Butterfly Box with three improvements using OpenSCAD.

• You can customize a monogram on the front bottom face (originally SBFB_FRONT_TITLE.stl) with 3 or 5 characters in any font. The picture shows my child's initials in a Gothic font. Customization requires OpenSCAD.
• Added a retaining slot inside the base (originally SBFB_BOTTOM.stl) to trap the drawer spring and hold it in place, so glue is no longer needed. This allows the spring to be printed in PETG, which is hard to glue.
• Added a color change at the bottom of the main box (originally SBFB_MIDDLE.stl) so that it matches the color of the base for a more continuous appearance, if the base and box are different colors as shown in the images.

Customizing the monogram

The monogram STL files aren't included here because they won't be useful to anyone who doesn't have the initials I set up. You need OpenSCAD to customize the monogram.

The first thing to do after opening the .scad file is to set the "path" value to the path where the original Secret Butterfly Box STL files reside on your computer.

Set the "initials" value to some text either 3 or 5 characters long. Set the print="fronttitle1" to render the STL file with the engraved letters on the bottom surface in the print orientation. Press F6 to render, wait a while, and when it's rendered press F7 to export to STL. You need this file for both multi- and single-material printers.

If you have a multi-material printer, export a second STL file to fill in the engraved spaces with letters of a different color. Set print="fronttitle2", press F6 to render, and F7 to export the STL file. Load both STL files into the slicer as one object with different color parts.

If you have a single-material printer, you can either print just the engraved part and leave it as is (optionally painting the indented letters), or you can set your slicer to pause the print on the fourth layer to allow you to change filament, to give the monogram a different color. The color change would be visible only on the left and right ends of the small bottom face parts.

Multicolor box

For a multi-material printer, import the two STL files in this Thing, sbfb_middle1.stl and sbfb_middle2.stl, into the slicer to be printed as one object. Set the bottom part to your desired base color, and the top part to your desired box color.

For a single-material printer, use the original STL file (SBFB_MIDDLE.stl) and set your slicer to pause the print when the base of the box finishes, so you can print the bottom in the base color and print the rest in your desired box color.

Installing the drawer spring

Insert one end of the spring into the slot, install the drawer, and try to close the drawer all the way. No glue is needed.

When I printed the drawer spring in PETG, I found that it would not compress sufficiently for the drawer to close. Apparently the bends in my spring were too thick. I had to snip off four zig-zags to make it fit.