I use sheets all of the time for my machine quilted quick quilts or for quilts that will see frequent washing. Often they are the 200 thread sheets and they wash and wear well. It is no problem to quilt them on the machine and it's great not to have to piece a back. I bought twenty sheets this past week for conmmunity quilts for $100 and you couldn't buy much yardage for that price as quilting fabric in Canada starts at $10 a metre unless you find a fantastic sale. If you're still not convinced, use a sheet on your next community quilt project and see what you think. I always try to buy King size sheets so I'll have extra sheeting to make matching pillowcases which are great to use with your quilt or use to store your quilt.