Making your own cloth diapers out of old bed sheets is an economical way to expand your diaper stash without having to spend a lot of money. Although you can make a range of different types of cloth diapers, including fitted diapers with snaps, the simplest diaper to construct out of bed sheets is a prefold diaper, which consists of rectangles of fabric arranged and sewn with extra folds in the middle. The resulting rectangular diaper (which you pin into place on your baby's bottom) has two to four layers along both sides with six to eight layers of fabric down the middle for added absorbency.
Obtain flannel bed sheets. Although you can make your cloth diaper out of any type of bed sheet, flannel bed sheets provide more softness and absorbency than most other types of fabric used for traditional bed sheets. In addition to recycling your own old flannel bed sheets, you can also frequently find inexpensive flannel bed sheets at thrift shops and resale stores.
Cut your outside flannel diaper fabric. You can cut the fabric to create a custom-fit diaper for your baby or you can simply follow the sizing guidelines for traditional prefold diapers. According to Little-Lions.com, an online cloth diaper supplier, regular prefolds (good for babies who are 15 pounds or more) typically measure about 13 inches wide by about 18 inches tall after shrinkage (see Reference 1). Since your flannel bed sheets are already washed, you don't need to worry about allowing extra fabric for shrinkage. To create a flannel prefold that is the size of a regular prefold, cut out two rectangles of fabric from your flannel bed sheet that are approximately 13.5 inches wide by 18.5 inches tall (including 1/4 inch seam allowance). These will be the top and bottom layers of your cloth diaper.
Cut out and stitch together your soaker diaper fabric. To determine the correct width of your diaper soaker, divide the complete width of your finished diaper by 3; in this case, 13 inches divided by 3 equals almost 4.5 inches. Therefore, you should cut six or eight 4.5-inch-by-18-inch strips of flannel bed sheet fabric, depending upon how much added absorbency your baby requires in the soaker area. Match the edges of all your soaker pieces and sew all of these soaker pieces together using a simple straight stitch to create a thick soaker panel.
Sew the soaker panel along the inside center of the outside diaper pieces. Lay one outside diaper panel wrong side up and position the soaker panel along the inside center of the outside diaper panel, leaving 1/4 inch along the top and bottom of the diaper panel for your seam allowance. Lay the second outside diaper panel right side up on top of the soaker, creating a diaper sandwich with the soaker panel between the center of the two outside diaper panels. Match the edges of your outside panels and pin them in place. Stitch a simple straight stitch across the width of the entire diaper about 1 inch from the top of the diaper to secure the soaker panel in place. Repeat this process for the bottom edge of the diaper as well.
Hem the edges of your flannel prefold diaper. Fold the top edges of the diaper panels inside the diaper about 1/4 inch and sew them into place with a simple straight stitch. Repeat this process for the bottom edge of the diaper. Fold the left-hand side edges of the diaper panels inside the diaper about 1/4 inch and sew them into place with a simple straight stitch. Repeat this process for the right-hand side of your diaper as well.