1. Measure the diameter of a circular pet bed insert. Add 1 inch for seam allowances and make a circle pattern this size.
2. You'll need to determine how many blocks to create. Use this formula to determine how many 3-1/4-x-5-1/2-inch rectangles you'll need: pet bed diameter in inches x 3.14 divided by 2.75 inches (round up to nearest whole number).
3. Assemble and join enough hourglass blocks and solid squares to equal the circle pattern.
4. Cut one circle each from the pieced fabric and a coordinating backing fabric.
5. Join rectangles to make a pieced strip, then join ends to make a circle.
6. Sew pieced circle to the pet bed circles with a 1/2-inch seam allowance, inserting a long zipper in the bottom seam to make the cover removable for washing.