1. Cut two 25-1/2-inch circles from print fabric. Cut two 25-1/2 inch-diameter circles from lining fabric.
2. Cut bias strips of contrasting fabric; sew the strips together end to end to make a piping strip long enough to go around a fabric circle. Fold piping strip in half lengthwise with wrong side inside. Slide piping cord inside folded strip. Using a zipper foot on your machine, sew long edges together, stitching close to cord.
3. Place piping on right side of a print circle; align raw edges and baste, clipping the seam allowance as necessary.
4. Layer print circles with right sides together; piping will be contained inside. Pin, adding zipper according to manufacturer's instructions. Using a 1/2-inch seam allowance, sew print circles and zipper together; clip seam allowance. Turn right side out through zipper to complete the bed cover.
5. Layer lining circles with right sides together; stitch together using a 1/2-inch seam allowance, leaving an opening for turning. Clip seam allowance and turn right side out.
6. Fill lining with shredded foam. Stitch opening closed. Insert filled lining into bed cover; zip closed.