I AM JUST LEARNING TO MAKE SIGNS SO TAKE MY ADVISE WITH A GRAIN OF SALT.
PAINT THE LETTER FIRST.. LET DRY... THE ROLLER YOU NEED IS A SMALL ROLLER WITH A TIGHT MAT... ROLL OUT MOST OF THE PAINT ON A SCRAP OF CARD BOARD. THEN ROLL AROUND AND OVER THE LETTERS VERY CAREFULLY. GO TO http://www.precisionboard.com/ WATCH THEIR VIDEO'S ONE SHOWS A MAN PAINTING LIKE I SUGGESTED TO YOU.. AGAIN I AM JUST LEARNING... ALSO GO TO THIS SITE AND ASK THE SAME QUESTION http://www.3dsignforum.com