Laser Toner Transfer Paper for PCBs

Set the iron to 'Linen' or as high as the iron will go. We need a fairly hot iron because we're going to be forcing the toner to remelt and subsequently bond to the copper blank PCB.

If you can, preheat the PCB, using a heatgun can achieve this quite well. A preheated PCB contributes to a better transfer at times (for small circuits/boards there often isn't a noticable difference).

Turn the paper with the PCB pattern over and lay it face down onto the blank PCB (that's why should print the artwork as MIRROR).

The critical part...
Apply the hot iron down onto the paper and PCB, pressing them both flat and putting them under pressure. Do not move the iron around. Leave the iron to rest on the paper for about 10 seconds. Reduce the pressure a little bit and slide the iron left/right, up/down a few times. Do notswivel/twist the iron on the paper, this will result in the paper most likely shifting and ruining your work. If the paper does shift then all you can do is scrub the board back, print a new copy and start again.

DO NOT LIFT THE PAPER

Waiting for the PCB temperature cool down to the temperature that you filling not hot or room temp.
After the temperature of PCB cooling down, you can remove the transfer paper easy, the toner on the paper should be transfered to the PCB mostly(Average of 99.8%), for the area that toner missing on the board, use the oil pen to patch that.

Congratulations, you're done. The PCB is now ready to be etched how ever you prefer. You can store your boards for as long as you like without having to worry about the toner degrading. This is very useful if you want to wait to do everything as a single large etch batch.