I've made these pillowcases and, yes, takes me more than 20 minutes. I count the cutting, sewing, and pressing in the "time." When sewing up the side and end seams, I use the French seam, which is sewing the seams with the wrong side to wrong side together, trim seam to a little less than 1/4 inch and then pressing with right side to right side to sew the 1/4 inch seam on the inside These made great kids' pillowcases because they are so durable. Our great grands love them pillowcases for their room. The last ones I made were monster trucks and Superman.