Vinyl dye is generally used in re-coloring vinyl upholstery in vehicles. A vinyl dye, instead of spreading over the surface, seeps into the surface where it is applied. And as a result the color does not peel or chip off. It is very much useful in coloring plastics.
While re-coloring soft plastics I prefer vinyl dye because in case of normal colors it puts a coat just over the surface. But vinyl dye when applied can seep deep and colors from within. This is because the vinyl dye is extremely thin. And the surface details, for e.g. the engravings or the relief are not affected at all. The impressions remain visible. And the paint does not peel or scratch off. This is really the nicest thing about vinyl dye.
Vinyl paint does not adhere properly to metal surface. And one peculiar thing about vinyl paint is that the dye is not to be applied to a surface that has been previously spray painted. So if you are painting a dark colored surface you will need to apply white vinyl dye first. And then you get to apply the color that you intend to put on the piece. Otherwise, if you apply the final color directly to this previously colored surface, it will leave you with a tint that is a mixture of the old and the new paint. So if you want to get a perfect finish while repainting a previously spray painted surface you better apply white vinyl dye first.
Another nice thing about painting with vinyl dye is that you are saved of the labor of priming and sanding. Unlike other spray paint, vinyl dye is newbie proof. While applying the first coat, make sure you are covering more than 75% of the surface. Wait for 5 minutes before applying the second coat and for 10 minutes before doing with the final coat.
Also if you are intending to do case moddings you better use vinyl dye. The most common aspect of case modding is painting. I have noticed that plastic surfaces are quite difficult to paint. And vinyl dye is a cure to your ‘paint-a-plastic’ predicament.