Where Can I Buy Alpha Decals for Firing onto Ceramic?

I am searching for all sized letter decals for firing on china. I am in the process of painting ceramic tiles and need these decals to fire on for the lettering. It is very difficult to get the letters perfect using pen work or even a brush. Do you know where I can purchase decals for firing on china or do you have any suggestions?

Thank you,
Patricia

See my answer to Patricia's question about Where to Find Alpha Decals for Ceramic.