What happens next?

How to put on a race bib
Pin the bib after putting on your shirt.
For the optimal fit, wait until you put on the shirt to pin the bib. The fabric rests differently on your body than it does against a flat surface.

OPT:
--The edges are almost the same line, as they would be from chest to belly. When you pin the bib, pay special attention to the most important parts of the bib that are not covered by the shirt: the back of the neck, earlobes, chin area, hip and ankles.
--When you're wearing the shirt, you'll be able to make sure the bib feels comfortable against you. Make sure you're careful when using safety pins.
--Make sure that the bib is on the neck or neck. Simply smooth it over the bib, and fold the left end under the right one, to bring the right end to your elbow.
--Do not pin at the top of your head, out of position. Grasp the front portion of the bib, but leave the seat belt in place.
When you're wearing the shirt, you'll be able to make sure the bib feels comfortable against you. Make sure you're careful when using safety pins.