Eroding vegetal tissue ?

[Externet]

Hi all.

At a store, I found framed between two glasses, a bunch of tree leaves missing its 'green' tissue, and nicely dyed and impregnated in several colors, and gold? powder. Yes, bought it. Too nice (or unique) to pass.

It may be a common practice among people that does manual art and that type of adorns, drying plants, etc. but I never saw such thing before.

 

The question is; how is it done? What chemical can erode tree leaves, leaving only its fibrous skeleton, looking as a 'gauze', with only the natural pattern of the tiny leaf veins.

Hope the image inserts. It may seem double exposure, but it actually is the fibers shadow on a blank paper placed behind the frame.

 

Miguel:-)