I layed out the dahlia on the dining room rug over an old sheet. It's a very flat and dense rug and I can't iron right on the hardwood anyway. I pinned it at all the points and sprayed it with the starch.
It did really well. I did have a some fullness around the yellow fabric row (for some reason) and I was able to ease it out and then iron the heck out of it. I'm going to let it sit for awhile and maybe starch it again.
Thank you for the ideas and information.