Originally Posted by ghostrider

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.