I know this has been touched on before and there's never been a 100% answer for under what circumstances do inkjet decals bleed or blurr.
Still an unanswered question but let me toss out some observations.
I did some decals on my inkjet, I forget who's paper brand. I sprayed the sheet with no-name hardware store clear acrylic (Harris). The decals went onto an enamel painted surface but I had a couple of WIA bogies (wrinkled, split, etc) that I randomly stuck on the painted shop shelves just for the heck of it. Home Hobby Decorating Montage :)
The original sheet shows no bleeding whatsoever. That says to me that the clear spray had no affect. Those that were exposed to water and put on the enamelled surface show just a tad of bleeding after several months. No overcoat was applied. Very minor and not objectionable except to the most critical eye. Those that I stuck on the latex painted shelf have bled objectionably.
I think there's a trend here. Inkjet decal paper is intended to be absorbent of the ink just by its nature. I think that also implies that its hygroscopic and will continue to absorb moisture. The latex paint example is telling. Latex paint is also hygroscopic and it would seem the moisture affects the decal from underneath.
No great claim or revelation or question here...just an observation that may be helpful in Inkjet Decal Management ideas.
-Bill