While selecting the best "standard" size for our pillowcase (which is 20inches by 30inches), we looked at lots of pillows and pillowcase and found as much as a 4 inch difference. This difference could make your pillowcases look too big or too small. Over the years the standard size of pillows has grown to what used to be called queen size. Todays standard size pillow cases is just 6 inches shorter than a king size. Older pillows and pillowcases may not fit with new ones. Older pillowcases may not hold the new larger standard pillows or the over stuffed pillowcases. To make sure my displays look their best, I match the new standards together! If you want us to custom make pillowcases to fit older pillow, please send us the measurements.