Hello.
Well, I wish I had some more helpful advice for you. I am so embarrassed to admit I ordered the mini template a few moths ago and haven't used it yet. :oops: I have used the other envelope templates at a stamp camp with my upline. We were using it to make a card so we used cardstock. I think I have seen some thinner paper in the SU! catalog to use for making envelopes to mail cards in. I can't remember though and I am out of town so I don't have my catalog handy.
I did a search in the gallery for envelope template and there are many beautiful samples. The cards use both vellum and cardstock for the envelopes. I will post the link for you.
When I get back home I am breaking out that mini template.
I hope this helps and wasn't just confusing. Have a wonderful evening! 
Gallery at Splitcoaststampers
envelope template
