if you are going to hand quilt you will want an inexpensive (loose-weave) sheet. the higher the thread count the harder it will be to hand quilt. that is the biggest reason that 'they say' do not use sheets is because the thread count is alot higher than quilting cottons and makes it difficult to get a needle through by hand, by machine sheets work fine. so, i would put together a small practice sandwich and try it out before committing to a whole quilt.