To wash, Just roll off about 8 yards and cut. I know that we spent a lot of time planning our cutting out and you are probably wondering if we should take that into consideration before we cut. The short answer is, we shouldn't. There is no way to figure out how much the fabric will shrink. You can plan all you want and then you will be mad because it is 3" to short or you have a left over 10". So, 8 yards is about the perfect size to wash well in a large washing machine, and it really will work out ok when you cut, trust me.
I do not measure with a tape measure, just eye ball it, or use your arm as a guide. Your nose to your fingertip is roughly a yard.
Wash with warm water and use a mild detergent. I do not go to a laundry mat! You never know what was in the machine before you got there. I use a lot of white fabric. Grease is your nemesis! Also if you are using a dark fabric, left over bleach can be in the machines. Not a good thing. If you wash 20 yards of fabric at a time it will stretch out of shape and you will have a mess on your hands.
Put the fabric in the dryer. You will have to untwist the fabric about every 20 minutes. Sorry, there is no way around it. It turns into a rotating fabric ball, and the center never gets dry.
As soon as it is dry, remove immediately, or you will have a wrinkled fabric ball on your hands! I usually don't re-roll my fabric on the bolt. I just fold it as smoothly as I can to prevent wrinkles. I usually use my husband for this; his muscles are better than mine!