Hi,
I’ve done some foiling like this for Christmas Cards in the past. It’s pretty neat and easy to do on paper.
I don’t know if this video on Laser cut foil has been posted in the forum, but thought it would be a good fit in this shiny topic.
The product allows you to apply the foil directly to the substrate, then raster away parts of it, leaving the unengraved area foiled. Or, you can vector engrave, then peel away part of the foil, leaving some with the original material exposed and some foiled. Even apply to cheap material, cut it out and get the look of shiny metal on the surface of a shape.
Here’s one vendor to give you an idea of the price. A 6" x 25’ roll for about $32. With judicious trimming coupled with the Glowforge camera alignment, I imagine this roll could go pretty far. I’m definitely going to try it.
http://www.johnsonplastics.com/red-6-x-25-engravable-laser-foil