How to use blue press and peel transfer foil for PCB etching?
You transfer the image onto the dull side, place that in contact with the copper, and iron on the other side placing a plain sheet of paper between the iron and the P&amp;P stuff. Here is a non-hacked web page.

Members of the Homebrew PCB Yahoo group have found that shiny magazine paper works just as well as that expensive Press and Peel material, and costs nothing, just use sheets from an old magazine. I've tried both, and can confirm that. Moreover, you don't have to worry about which side is which! :) I get much better results using transparencies printed on an inkjet printer with the conventional photo-etch process using precoated positive resist boards.