My wife bought me a Graupner Otto Lauffer some years ago and the lettering in the kit wasn't water slide but a vinyl sheet.... the letters weren't individually printed, a way around this was to cut them out ... a bit of a task and not at all neat.
I painted the hull semi matt black which then highlighted the shiny vinyl edging around the lettering.... awful.
I ended up buying a sheet of individual vinyl letters of the correct size and font...... much better and guaranteed to stick and remain stuck.
Regards
Terry H