I have found this method works the best. The sizing and chemicals used in making fabric needs to be removed before the wrinkles will come out. Soak and wash dry till damp then press with a hot iron will work.
Originally Posted by
Bneighbor
Try warm water, the put in dryer but only to damp. Then press with very warm iron. The small amount of water left in the fabric may produce enough steam to draw those wrinkles out.
You might want to take the fabric and show the owner the issue.