There are foils used with laser printers to create gold and other metallic looking logos for fancy stationary. I used to buy it decades ago. If I remember correctly, it was/is called Omni-Chrome or something like it.
I also used it for making dense artwork as described below. I think that company is just using that same material and re-labeling it as special product for PCBs.
Bertho
From: Confidential Sent: Saturday, September 01, 2012 05:58
There is a relatively easy solution. From the PCBfabinabox product there is something called TRF, or toner reactive film. You apply your toner to your board, then place a piece of this toner film over and run it through a laminator. Peel the TRF film away and it will leave behind a very opaque substance on the PCB that only sticks to the toner.
Perhaps this might help.
http://www.pcbfx.com/main_site/pages/products/toner_foils.htmlNeill
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