Not usually.
I've pre-washed reds and very dark blues before.

I heard a quiltmaker tell Alex Anderson that she never washed her fabrics. Alex said," What happens if your fabrics bleed?' The lady replied........."Then i make another quilt." I think that is a pretty good philosophy.......

I usually wash my fabric

I never wash mine,unless its a bleeder,then it goes into a color catsher bath. As for shrinking,a steam iron is hotter than hot water or a dryer. I always use steam and I have never had a problem.

I don't wash...(pun intended)

I always prewash. I used to do it to make sure I don't have shrinkage or bleeding later... But now there is another good reason to prewash fabrics... BUGS!!
Bugs of all kinds are becoming more and more of a problem.. and with the bed bug epidemic growing every day I never bring anything fabric past my laundry room.. which is where I come into my house from the garage. I not a bug-a-phobic, but I'm not going to give those little varments a chance around here!!

I always wash my fabric before it even lands in my sewing area.

Reason: removes sizing, gives me a heads up for any bleeding fabric (wash like colors together along with one or two Color Catcher sheets), fabric might not be on straight of grain off the bolt, ironing after washing helps get it on straight of grain. Then there is the issue of importing nasties...bed bugs was a heavily discussed subject not too long ago. Then, most of the shrinkage is taken care of.

Just me, and how I do it.

Oops, just realize Judie posted the bug issue also...like minds.

I only wash flannel because of the degree of shrinkage.
I love using flannel as a backing. it adds an extra degree of warmth

Candace i AM WITH YOU, but my pre wash is i put my material in a bucket and turn on the hot tap. I leave it is the water till it is cold. Hand it up and then iron. I also feel all that hard work and then the colour runs - OH MY GOSH, cannot bear that. I like the smooth ironed look - not the wrinkled look.

I don't wash my fabric. I do tell everyone to wash in cold water and wool lite though just in case.