What you need45-inch wide (1.2m) Tightly woven fabric
Start by cutting a rectangle of your fabric to measure 8 x 41 inches (20 cm x 1 mt). Sew the two long edges together to form a 4 inch (10 cm) tube making sure that you are sewing on the wrong side of the fabric as we will turn it right way later.
Sew one of the 4 inch (10 cm) ends closed using double stitches on your machine.
Turn the tube right side out so that you can now see the right side of the fabric. Use a yard stick to push all corners out and smooth.
Pour the kitty litter into the tube. Leave 1-inch from the top end empty.
Turn in 1/2-inch of raw edges on the end.
Top stitch this seam closed.
Photo Credit: markhillary off Flickr.