For knife edge pillows that are sewn shut, I cut my fabric 1" larger than the pillow form and use a 5/8" seam. That way the "finished size" of the cover is actually 1/4" smaller than the insert size so it is plump without being stressed at the seams. I also taper the corner seams slightly to avoid pointy ears at the corners...hate those. You will need to cut extra fabric if you are making removable covers.
Last edited by ghostrider; 12-01-2011 at 03:08 PM.