This is a project that I did for Christmas presents - I made rice bags to be used as a hot or cold pack. I love these little babies! We keep one in the freezer all the time, plus another on the shelf waiting to get heated in the microwave. Hot or cold, I got it covered.
I chose some flannel to make snuggly cases, plus muslin to make the actual bag that holds the rice. Stick with cotton or wool fibers. You don't want man made fibers melting in the microwave! I was making a couple dozen bags as gifts, so I picked up the 25 pound box of parboiled rice from Sam's. It was clean and filled about 2 dozen bags.
I wanted a bag big enough for an arm or leg boo boo but small enough to tuck on my creaky neck. I decided to divide a yard of muslin into 8 pieces, to make the finished bags about 8" by 11". You can make these any size to fit your needs. I folded the piece over to sew each side. Serged the seams to provide 2 layers of stitching in hopes of preventing rice from wiggling out. Then I stitched channels in the bag to hold the rice evenly, rather than one big lump.
I filled the channels with rice about 2/3 of the way full. It was simple enough to use a funnel and small cup. I wanted enough rice to hold the heat or cold but not so much as to make the bag stiff. You want it flexible so you can wrap it around the curvature of your body. The open end got folded in and carefully stitched on my machine. I got lucky that I didn't drop one and spill rice everywhere, LOL. Tada! A finished bag.
Some people stop here but living in the country, we sometimes get bloody boo boos. I wanted a 'pillow' case to add softness and an extra layer to smooth over any poky rice grains. Maybe you know more about velcro but I worried it would melt in the microwave, so I made simple overlapped bag cases.
I serged the cut edge that would make the overlapped ends. It wasn't necessary but I love my serger! The overlapped opening was located close to one end, so that the rice bag didn't have to be folded in half and stuffed into the case.
This project was super simple and whipped up in no time. I tucked the rice bags into their cases, then slipped them into big ziplock bags. We keep ours IN the ziplock when not being used. My theory is that the rice will draw mice and I despise vermin.
I have considered making a bigger, flatter rice bag to be heated and tucked into the foot of our beds during winter. You can also make a smallish bag to be kept chilled and used on puffy eyes. There are so many ways to customize these bags. They really are versatile. If you try this, be careful to only microwave for a minute or so. You don't want them too hot. My microwave can heat them for a minute and a half and still be comfortable. And unlike a heating pad, they won't get hotter and burn you.