I've made several of these - one for each grade of sandpaper I use from 80 grit up to 400 grit. The hook and loop sandpaper is available from numerous sources. I purchased the velcro from a local bandsaw blade supplier which also sells sanding supplies. It can also be purchased from sewing stores or online sanding supply houses. The body is cut from a 2x3 pine and the sole plate is made from a hardwood - maple in my case. A template and set of plans is included in the PDF below.
Try one for size and adjust the dimensions as required to suit your hand size. I made a similar set for wet sanding without the velcro, using 3/4" wood. But they don't feel as comfortable as those which are 1" thick.
Enjoy and have fun making them. :)
Thank you for the submission.
Lou
I have discovered you can make your own hook and loop sandpaper by attaching felt to the back of regular sandpaper with spray adhesive thus creating papers that may not be easily available.