My version is similar - I also used Ikea fabric and a green backing. The unique feature about this green fabric is that it used to serve as the packaging from my West Elm duvet cover. I did have to split the fabric in two in order to make it fit, but it worked! And I was able to repurpose something that I just didn't have the heart to throw into the garbage.
The final shape was a result of my trial and error with cutting rectangles and trying to line up stripes, so it's more narrow than I expected. But I still love this fluffy piece!