Madame Mosley asked how I padded the hearts on the canvas below. Well, first I made long vertical stitches using 6ply of DMC floss. Then I went right over the top of those stitches with long horizontal stitches. Finally, I used Rainbow Gallery's Flair as the top fiber, and I think I did two courses of long vertical stitches.
I think the reason why I didn't get a lot of separation on the top layer is because Flair is a) relatively flat, and b) it's stretchy and was easily pull-able.
(Miss Jane from Needle Nest calls Flair "Barbie pantyhose" because it's a tubular nylon...tee hee!)