The first type of foil is called "Hot Stamping Foil" which has a special "sizing" or adhesive on the backside that when subjected to high heat and pressure, will cause the foil's color to permanently stick to any paper.
You've no doubt seen "Hot Stamping Foils" on almost every Greeting Card in the rack. This type of foil requires a metal "die" be fabricated and mounted in a device that looks like this image on the right. This is used only in mass-production of one design. The 'die' to be fabricated (as shown to the left as a gold heart shape) is put into a press and heated. Foil is then placed between the die and the paper and when pressed, the foil in the shape of the die is transferred to the card. Obviously, not the route we want to take when making just ONE image! A die is very expensive to have fabricated.
The second type of foil is called "Toner Reactive Foil" or TRF for short (a suffix you will see on all of our foils like "Metallic RedTRF").
While "Hot Stamping" foils use a sizing that will stick to anything when heated and stamped, "TRF" foils differ in the type of sizing applied to the back of these foils. This type of foil will only stick to where there is "plastic". Key here is that regular laser printers and copiers use "toner" (ink) that contains 55% styrene plastic! Any image created on a laser printer (or copier) can be colorized by any TRF foil by merely applying high heat and pressure over foil, pressing onto the toner image. This is where the laminator comes into play to achieve this transfer. After running through the laminator, the foil is peeled off leaving the newly colorized toner image.
With TRF foils, you can make just one image for pennies with no die or stamping machinery... just the laminator.
Print your image to your particular paper type
Cover the toner area with a foil color
Run both the printed page and colorizing foil through a laminator, peel off the foil and you're done!
Perfect for custom 1-up projects or even mini-mass production of wedding invitations, etc. And you can do it all "in house" without the support of anyone else.