It is recommended not to use pictures printed off of an ink jet printer when you are decoupaging. I had an experience with this before I was aware that it was a bad idea, in which the photo I coated turned all kinds of funny colors as the glue sucked the ink out of the paper.
Being that I am stubborn and do not have as many magazines as I would like to sort through, I found a way around it. Besides, what magazines would I need to have to obtain lots of pictures of gold and treasure? Some of you probably already tried this, but simply spraying your printed photos with 4 coats or so of acrylic sealant solved the run problem. I was worried at first that I may not have sprayed it evenly enough, but it turned out just fine.
It was a very simple project I was working on, but I will definitely need to use a different kind of glue to fix the paper onto the inside of the chest if I do it again. It had a hard time staying flat as it dried.