If you use cotton fabric, this can be popped in the microwave and the rice heats up. I added lavender to make it more relaxing. It’s about a 3:1 rice to lavender ratio. No instructions as I made this from memory of seeing ones other people had. Fill it 1/2-3/4 full to allow it to drape and mold to the spot. It can be made any size. This one is long and skinny so I can put it across the back of my neck. It can also be put in the freezer to use as a cold pack.