|My measurements were 15.5 inches wide by 19.5 inches long plus another 4.5 inches of diagonal
I sewed the right sides together leaving a hole at the bottom. Then, I flipped it to the right side, sewed up the hole and sewed the sides of the envelope together.
To make them look a little more festive, I added ribbons and buttons -
Here's a tip that I learned the hard way... then forgot and learned again -
If you cut the rectangle with the point going up (like it is shown in the first photo), make sure your fabric is upside down. Or you can cut the fabric right-side up with the point coming toward you. Either way, it was opposite of how I was thinking, so I cut it out incorrectly twice. And that is why the "French" fabric is on the inside of two of them. But I like that they are all unique.