Blue Blizzard Fleece This fabric is a happy blue fleece with darker blue swirls and snowflakes. It has a small amount of stretch that runs the width of the sling. Fleece slings are made to fit a little more snug than a cotton sling because they stretch a little with baby's weight. Do not adjust your size to compensate for the stretching as I have already done that. This is 400 gram anti-pill velour fleece.