To make a microwavable potato bag, sew together a 100-percent cotton decorator fabric to a cotton liner and cotton batting with cotton thread. The bag catches on fire in the microwave unless you use 100-percent cotton for all materials in the construction.
You also need scissors, sewing pins, measuring tape, and a needle or sewing machine. An iron and ironing board are optional. Before cutting and sewing, measure the inside of the microwave to ensure that the bag fits properly. The bag must be able to rotate freely if the microwave has a turntable. After measuring, cut the cotton decorative fabric and the cotton fabric lining to the same size. Place the cotton batting between the decorative fabric and the lining, then quilt the three fabrics together. Fold the edges of the fabric together to create the hem. Fold the sewn-together fabric into a square inside out, and fold the ends in the center with one end covering the other 1 inch over. Then sew around the edge with half of an inch allowance. Finally, turn the bag right-side out, and wash it in the washing machine before use. You should not microwave the bag unless food is inside it.