Fabric identification

I have this 50's/60's Cay Artley dress that has no materials tag inside. It is pretty light, with a slight vertically crinkly texture- maybe some kid of crepe? It has some light staining and I really need to hand wash it, but I was wondering if anyone had any experience with this material and would know- 1. Can it stand up to Oxiclean, or would gentle detergent be about it, and 2. Will washing have any affect on the pleating on the skirt (I would be hanging or laying it dry).

Any help is appreciated! Please see pics for detail-

 

A thought about Maggie's post that you sometimes see shrinkage at a zipper.
Fabrics like nylon don't shrink. In the 50's, zippers were still cotton. Cotton does shrink; this wasn't a problem if the garment required ironing because once the zip was wet, it could be pressed to lengthen it again.

 

To update- I hand washed in cool water, with gentle detergent and all the stains lifted beautifully- even the nasty sweaty back stain that I thought would be there for good. I hung it up outside to dry in the warm air and it retained the pleats no problem. Thank you all for your suggestions!