There are special medias designed for solvent printing. Most sign supplies will refer to it as "digital print media". I do not know the chemistry behind it, but I believe the idea is the media will absorb the ink, whereas if you just print on any regular vinyl, you're essentially just slapping a layer of ink on top of it. Thus you may not get the same weather/water/uv resistance as you would if the media was designed for solvent printers.