Jays,
My rear plates are painted on the sides of the tail. You would have to be mighty brave (or foolish!) to attempt them freehand as it is no easy thing to correct a mistake. I ordered a stencil of the whole plate (x2) from Classic Transfers who provide a very good service. I went to considerable lengths to position them correctly and evenly on the panels. And yes, I painted a black background under them. If I'm honest even brushing in the stencils neatly was about the limit of my own skill! But the results are pleasing.
Regarding font size, I have never received a comment or complaint.
My rear plates are painted on the sides of the tail. You would have to be mighty brave (or foolish!) to attempt them freehand as it is no easy thing to correct a mistake. I ordered a stencil of the whole plate (x2) from Classic Transfers who provide a very good service. I went to considerable lengths to position them correctly and evenly on the panels. And yes, I painted a black background under them. If I'm honest even brushing in the stencils neatly was about the limit of my own skill! But the results are pleasing.
Regarding font size, I have never received a comment or complaint.