Weighted lap pads and weighted stuffed animals are great for calming the nervous system, increasing sensory input for sensory seeking kids, and increasing proprioceptive input. The deep pressure is soothing to children and can decrease sensory overload and aid in regulating the body.
I recently made a few for my classroom groups and found an inexpensive way to make several. I am not an expert on a sewing machine so knew I didn't want to sew each individual sack of filler for the pads so searched for ways I could avoid this step.
I found large beanbags filled with Poly Pellets on Amazon.com. These bags are "regulation corn hole beanbags" and were about $12 for a set of 8 so I ordered two sets to test them out. The bags weigh 14-16 ounces a piece. With 16 bags total I made a variety of weights and sizes for my preschool-4th grade classes. I found fleece and textured material on sale at Joanne Fabrics bringing my total expenses for 4 lap pads (One 6 lb rectangle, one 5 lb long skinny pad for over shoulders, 2 small 2 lb rectangles) to approximately $40.
Note: If you're not especially comfortable on a sewing machine (like me) I recommend the long "snake" lap pad, it was much easier and quicker than the rectangular lap pads.
Extras: had some Poly-Fil fluff on hand so I added a handful to each section but I don't feel this is necessary for a weighted lap pad.