This will help prevent your canon batteries from shorting out while they are out of the camera by covering the contacts. I made these because the Canon covers that come with the batteries fall off way to easy and prone to getting lost. Another nice thing about this is you can print them off in different colors to tell the difference in a quick glance, I have my official Canon batteries printed in white and my aftermarket batteries that I like to use in the battery grip printed in red. When printing make sure to have the closed end down like I do in the picture for the best quality. Also when you first use them it WILL FEEL TIGHT AT FIRST but just put the battery in and out a few times and it will be snug enough to stay on but loose enough to pull right off, however if you're using ABS or your printer is not 100% calibrated you may need to up the scale a little bit.
If you print this and have the time, please upload a pic to the "I Made One" tab. I love seeing my designs get printed :) Thanks!