My top is almost finished and I've used precuts and unwashed yardage only. The batting is also unwashed. The backing I was thinking of making from used sheets (pink!) I bought from a thrift store which are soft and a really nice quality. Will I have loads of problems since the backing will be washed and the top and batting won't be and end up with a wonky quilt? Should I try and pre-shrink the top before quilting?

Help