Sheets must withstand a great deal of wear and tear over their lifetime. Tossing, turning, twisting, bunching, washing, drying, getting stretched, getting pulled, the threads and weaving that make up the fabric of your sheet are tested time and time again. No sheet is meant to last forever, but there are ways to extend the life of your sheets. For example, the queen fitted sheet on your guest bed (or your own bed, for that matter) will last longer if you minimize how much twisting and pulling it is subjected to on a routine basis.
You can do this by getting a queen fitted sheet that fits properly. A fitted sheet should fit the bed snuggly, but not be overly tight. If it's too tight, the threads are strained and the sheet is likely to pop off while someone is sleeping. This tug of war between straining the threads, releasing them, and then bunching and wadding them up puts undue stress and wear on the fibers. Likewise, if a fitted sheet is too loose, it will bunch underneath the person. By naturally tossing and turning in their sleep, toes, fingers, elbows, knees, and other joints will pull at or dig into the excess fabric. This also causes strain and early wear.
Measuring your mattress will help you fit a queen fitted sheet properly to your specific bed. Proper fit, while not a guarantee against normal wear, does decrease early wearing and unnecessary strain on fabric fibers. Keep in mind the changes a particular fabric is likely to undergo during the normal washing process, as this will affect fit over time. If a sheet is too snug brand new and made of a fabric prone to shrinking like cotton, odds are it will become too tight after a few washings. Likewise, if a sheet is too loose and made of flannel, a fabric known for stretching, normal laundering will change its fit over time as well.
While properly fitting your queen fitted sheet is not the only way to a longer sheet life, it does help. Other factors such as thread count, detergents and cleaners used, and your choice in fabric will also dictate the life of your sheets. However, making sure of a proper fit is a costless means to extend the life of your bedding. Surely a few extra minutes to check dimensions to match the right size sheet are well worth the benefit of enjoying your purchases for as long as you can.