There are many ways to accomplish what you want to do, if I read your initial post right. Don't get too focused on one method. Xfers such as Pantone Letrafilm are fine, but tear easily, can shrivel or react badly with gloss coats, and may not come in the size/font you want. As alternatives, I would suggest using a print-out and a copier to get the right type face and size, then using a sharp knife to cut out a stencil. You may also be able to use the stencil to spray onto clear decal carrier film as opposed to spraying right onto the model. Experiment with some techniques to accomplish what you want - get creative. You may discover something none of us ever thought of doing, and it might prove handy in the future. If it were my project, I would freehand it with a good brush and give a light buff with polishing compound to smooth out the surface of the letters. Again, it depends. Inch high letters, like on a NASCAR model are very different from 1/16" high letters, like a name plate, and require special consideration. Good luck and have fun!