So, I decided to make some myself. This week, my favorite craft store ever, is having a sale on books of scrapbook paper. I found a 180 page book that was on clearance for $8 and received 40% off on top of that! So it cost me around $5 for a $20 book. Then I just bought some double sided tape and was ready to go.
First I made a template based on my card size. The side flaps are 1", bottom half is 3", and the top flap is 2".
I traced the template on the back of the selected paper.
This is what it looks like cut out.
Then I scored and folded the edges so they were all crisp.
All folded and ready to be taped.
Put a strip of tape on each side to connect to the side flaps.
And you have an envelope!
Now just do it a million more times to get the number you need. If I made the 180 envelopes that I could with this pack, they would end up being less than 3 cents each. That is pretty awesome for something custom!