We do use different sizing charts for pillowcases and fabric. We have found that pillowcases are often too narrow for larger sized dresses. You may always make a smaller sized dress than is stated in the measurement chart for pillowcases with the width but please do not make a larger dress than the measurement chart. For example: if the total width of your pillowcase is 36"... the largest dress that you can make is Size 4... you may make any smaller size with that 36" pillowcase but not any larger size of dress. People have asked us why we are now using the full width of fabric when sewing with 44" wide fabric. The reason we use that full width is because it gives us flexibility when fitting dresses in the field. We may run out of size 7 dresses and still have girls left... so we may have to give a girl a smaller dress that she can wear as a blouse... the full width gives us that flexibility.