Weighted lap belts, vests, small blankets, etc, all work by applying deep pressure. Kind of like a big hug without having to endure human contact. It is very calming and grounding. Some kids like to sit with a weighted blanket across their lap. I know a boy who likes it wrapped around his head, hoodlike.
Ours are made from fleece so they are soft to touch as well. They have channels that close with velcro. Inside each channel is a flattened tube shape filled with split peas. The tubes can be removed for washing, or to make the lap blanket lighter.
Making more is on my to-do list :roll:
So is making a puzzle quilt. Thanks for all the great links here!!