what is the proper way to advertise my t-shirt screen printing business to on campus organizations?

[ernestezie]

I am starting my own screen printing business and want to start out by [printing shirts for organizations that are on campus. I have the emails of the presidents of these orgs but I was unsure of how to sound when I email them and what exactly to say. I definitely want to tell them the what I have to offer as far as colors or shirts and different screen printing options but i want some ideas on how to word the email as to making them want to order shirts automatically!

something like don't you want to "rep your org" or something like this. I want the email to be proper but at the same time fun and exciting.
these orgs include dance troupes, modeling troupes, fraternities, sorties, interest clubs, etc.

any ideas