I took the idea from Amy Butler's Kindly Cards. I did revise the envelope and added an extra tab, so it could be mailed without the card falling out.
I had gotten some double sided scrap book paper.
the invitation itself would take a lot time to write! So, we decided to print them out on vellum paper. Double sided tape was used to keep it on.
We also used double sided table to enclose the smaller tab over the larger tab.
It didn't take too long to make. It took us a night to cut and tape.
So, what do you think?