I made an Elizabethan corset with plastic canvas bones and it works great! *disclaimer* I am a b-cup and slim to begin with so I do not require much in the way of support or winching in just some smoothing. If you have a larger bust or are making a waist squeezing corset steel is the way to go.

Mary McFadden spoke to my costume design class while I was in college. She told a classroom full of students, nonchalantly, that she used children in India to pleat her fabric. She said something about little 5 year olds having the best fingers for making the pleats. We were shocked that she seemed to think child labor was acceptable. Her designs are beautiful but her integrity is lacking.