A striping brush or spray gun may be used. Vinyl tape is applied as a "mask". Paint is then applied. Dry "masking" is removed.
Paint supply manufacturers produce pre-sized masking tape for the stripe desired.
A striping tool that uses a serrated roller. A different width roller can be installed in the tool to duplicate the paint stripe. A magnetic guide strip, when placed on a steel body part, can be used to help guide the tool for making straight or curved pin stripes.