Depends on how much the cresting paint is thinned and it can vary slightly from shaft to shaft. I'd figure about 20 +/- 10 grains. (I always double dipped mine chartreuse over white.) Cresting wraps are a better option because of their shaft to shaft consistancy and easy of application compared to dipping. I think most wraps are 8-20 grains depending on the manufacturer and type. EZE Eye may even publish weights on their web site, check it out.
http://www.eze-eye.com/techcenter.htm