From a textile book:
.....Many fabric companies in the quilt market use cotton that is 60 by 60 or 68 by 68, meaning that many threads per inch going both ways crosswise and lengthwise. P&B often chooses cotton that measures 75 by 75. A bed sheet is much stiffer and wouldn't be very easy to sew through, even using a sewing machine (it is murder to hand sew).....
So just know you will may have problems with machine quilting and the LA may also.