First, you should engrave it to make the images and text appear on the material.

To achieve a successful assembly, cutting the material precisely before moving on to the assembly process is vital.

After cutting and engraving, you will need to use glue or super glue to stack the pieces together, as shown in the image. Depending on the material, you may need to use supports to hold the pieces in place, but for 3mm basswood, you only need one support for each side.

Now, you can attach it to a keychain and slide it to reveal the word "YOU," which will form the whole phrase "I LOVE YOU."