There are two specialty foils to our system that when subjected to high heat & pressure will permenantly bond on top of any toner image.
The "GreenTRF" foil is used over a transferred circuit image to seal the toner for etching. The "WhiteTRF" is used for the optional "Silk-Screen" layer to turn the black toner text and component graphics white resembling a real silk-screened PCB.
When these specialty foils are subjected to heat & pressure, they will only transfer their color coating onto plastic. The interesting thing here is that toner consists of about 55% styrene plastic! So, by covering a toner image previously transferred to the copper board with one of these foils, and applying heat & pressure, the foil's respective color will completely cover and seal just the toner image itself - now just peel the foil sheet off and you're done.
This "GreenTRF" foil is used to seal the toner image against the etchant, resulting in a perfectly etched image.
Toner is a very porous material. If left alone on the board and etched, you'd wind up with micro-pitted copper (or even near- invisible hairline breaks) due to the porasity of the toner. It's just not a "solid" toner image. The etchant actually gets into the toner and works its way down to the copper resulting in very poorly etched circuit boards.
The "GreenTRF" solves this problem completely by encapsulating the toner image in solid plastic color. An absolute "must have" for producing quality boards with traces widths down to an amazing .005".
8" Wide x 15' Long
The "WhiteTRF" is used to create a very realistic silk-screened looking board.
To get a professional look to your circuit board, add a silk-screen layer from your circuit design software!
Your "silk-screen" image, comprised of text and component- part outlines is printed to the transfer paper, then transferred to the completed PCB the same way as did to make the board. However, this time you would cover the transferred toner image with the WhiteTRF and run it again through the applicator which will then convert the black toner to white.
8" Wide x 15' Long