Here is another thought on toddler sheets....Instead of a cotton top sheet, use polar fleece. The advantages are, it is as washable as the bottom sheet, it will not bunch up and slide around like cotton sheeting, it is instant warmth when you crawl in on a cold night, it can be used in lieu of a blanket on hot evenings, other bedding like quilts will stick to it and not slide off the bed with restless sleepers.