You need to make sure you're using inkjet decal paper, as you can also get decal paper for laser printers. I found this paper on Amazon UK, but others are available.
I'm not sure what the microscale one is, and can't find just plain decal paper on their site. If you are using inkjet paper, then it's maybe worth trying to find some Canon specific ones. Inkjet paper should work in any inkjet, but you never know 
It said for inkjets on the package. There were 2 sheets in the package and I gave one to a friend. He encountered the same problem.
I have also tried to give the sheet a coat of anti-shine. That seems to give the ink something to cling to but the printout still looks a pointillism piece.

The Amazon decal paper is unavailable for shipping to Belgium

That said, have you used it yourself ?
Canon is not an option as they only have iron-on transfer paper.