Measure the length and width of the rectangular dog beds for you to know how much fabric to buy. Double the length and add 5 inches (12.7 cm) extra each side to cover the top and bottom. For one that is 4 ft (1.21 m) long and 2 feet (0.60 m) wide fabric you will need 8 feet (2.56 m) to 5 inches (0.73 m) long by 2 feet (0.60 m) to 5 inches (0.73 m) wide. Wash, dry and iron the fabric before starting. This makes it easier to sew and makes it easier on your pet. Fold the fabric in half horizontally, then cut directly in half, leaving two pieces of the same size.
Place a piece of cloth on a flat surface with the back up. Place the bed on it and trace the outline with a pencil, mark the dimension or with pins. Repeat this step with the other piece. Place the two pieces together so that the two sides are back out, then put pins to gather the fabric for dog beds.
12 Photos Gallery of: Sew a Cover for Rectangular Dog Beds
Seam 3 inches (7.62 cm) from the line you drew starts, and sew 3 sides leaving one open, so you can enter the dog beds. Flip the cover to the right and put the bed inside. Sewing the open side ends. Cut off any excess threads and be sure.