If you frequent Pinterest you will recognition this Pillow Mattress.
|image from: Pinterest|
I have found two sites that give great how-to tutorials on how to make these Pillow Mattresses.
|image from: Southern Disposition|
Pillow Mattress Tutorial - (from a duvet cover)
|image from: No Rest For The Creative|
Pillow Mattress - Method I - Using 58/60" wide fabrics
The Pillow Mattress - Method II - Using 44/45" wide fabrics