In one of my recent project, I've done it in a different way.
This is what I call the "Combo Embossing" technique.
Here are the steps.
1. Paste a pattern paper onto the acrylic piece first. In my example above, I've added a piece of vellum and pattern paper in the middle of the acrylic piece.
2. Run it through an embossing tool. You will get an embossed image flowing through all layers.
3. Use some distress ink to lightly highlight the embossed images on the pattern paper and vellum.