I haven't experimented with mylar but I found someone who has, William Whitaker, find details on the Forum for Professional Portrait Painters and Serious Students.
Also found another forum of Studio 2012 where Kanevsky gave a workshop. There are a couple of posts sharing student's notes. The second student captured a point that struck me, "Another point that I have heard so often before. He said someone asked him about who his favorite teacher was. He could not remember a single teacher but his fellow students he could remember. People who are constantly feeding off of each other learn." I think this describes how I feel about my experience of blogging. I'm learning so much through everyone's reflections and art.
A classmate of mine in Open Studio also experimented with clear mylar sheets. She used it to create several layers which she hung behind one another with several inches in between. She set a light to shine from back to front with the intent that all layers could be seen superimposed on each from a front view or individually from the side view. It was somewhat successful but she needed more time to experiment with spacing and lighting. I should mention she used acrylic paint rather than oil.