For this project, I used 3mm thickness walnut plywood. I secured the material on my honeycomb using the magnetic pins. It's personal preference but I tend to run the wood grain lengthwise for a bookmark. If you plan to paint the engraved space on your bookmark, apply masking tape (I used blue painters tape) before engraving.

After lasering is complete, remove the bookmark from your machine and apply paint. I used acrylic art paints. Let the paint dry and remove your masking. Lightly sand across the surface to remove any paint that bled out of the engraved areas. 

I finish nearly all of my wood projects with clear satin enamel spray paint. It brings out the wood grain and protects the finished product. If you'd like, add a jute cord tassle.