I bought some Hobbs batting. The washing instructions say to dry the finished quilt flat. I don't know of anyone who has a place to dry a queen sized quilt flat. I'm working on a quilt for a church camp that I'm sure will be dried in a dryer. I also like to make crib quilts that get washed and dried in a dryer frequently. What kind of batting should I use for those. I plan on machine quilting them.
You can certainly toss the quilt in the dryer without a problem.
Laying the quilt flat to dry is a way of blocking it to the shape/measurements you want - squaring up the corner, adjusting a bit in the length for a straight edge, etc.
And, as you can see in this link, there are many, many opinions on the subject:
Sometime I block, sometimes I don't. And it has nothing to do with the batting. For most people, it's more an question of the "value" of the quilt to me, if it's going in a show to be judged, if they like that really flat look you get, or it needs a little nudge to be perfectly square.
Waem & Natural is a good one. get it at Joannes hobby lobby, walmart I think
If you are working on a quilt for a church you might be able to take the quilt to the church and lay it flat on the tables at the church. I have taken them to my church to pin them and am able to lay the entire quilt out because there is enough room and tables.
I use Hobbs 80/20 all the time and I machine wash my finished quilts in cold water and I dry them in the dryer and haven't had a problem. I'm not sure what kind of Hobbs you have, so I suggest you make a little sample - about a foot square with the batting in it and put a little quilting on it - and throw it in with your laundry. Measure it before you wash it and after to see if, or how much, it shrinks and how the sample looks after it's been washed. Most likely, it will shrink a little and give a little bit of a wrinkled, old fashioned look, but that might happen even if it is hand washed.