So I finally finished trimming out all of the save the dates (I printed 5 on each page). As well as all the return address labels. Now I could have just purchased sheets of pre-perforated Avery labels, but no, I wanted them to be a certain size. So, again with the double-sided adhesive.
I printed out sheets of the labels on a desktop printer, applied the adhesive and trimmed them out. Here is the final product:
I was once again able to use my istock pattern. I am about to head to the post office to get stamps and then tonight I will get them ready to send away!