Fixative sealer

Hi , ladies i need help. I’m going to work with pan pastels. My problem is , what do i use to seal the doll ? I can’t find info on what is safe to use on vinyl. Thanks

I use pan pastels and I just seal with varnish as usual, nothing special for the powders.

That is what I do too but as I am going along after every 3 or 4 layers of painting I do a layer of UMG mixed with water all over doll.