Love that one! I've been looking at different styles because I'm throwing my friend a baby shower next week. How did you arrange the diapers?
This is a bit confusing, at least, I'm not sure of the best way to describe it without showing you. I laid the diaperson their sides crotch to the right waist to the left, then overlapping them by half a diaper at a time I added one and rolled, then added one and rolled.
Once my roll was big enough that I couldn't hold all of the diapers at the same time anymore without my roll coming undone, I wrapped the entire bottom of the roll with a 1.5 in wide piece of ribbon still attached to the spool. (At this point the cake looked like the top teir minus the top ribbons.)
Once I'd made one complete revolution with the ribbon I continued overlapping a diaper and then wrapping with ribbon until the cake was the size I wanted. I don't know if that makes sense.
When I was finished I had gone through about 4 spools of ribbon. It's the ribbon winding throughout the entire cake that gives it it's stability. I used a stapler to fasten the ribbon to itself to secure the ends so as not to damage any diapers, and then used more ribbon on the top for decoration and added support. The bows are hiding my staples.
I found that if you use ribbon thiner that 1.5 inches, the diapers don't stay as well. I hope this helped a little! Sorry If I'm getting back to you too late, I was away for my computer for a few days!
P.S. New baby Layla is making good use of her diaper stash!