Certainly some helpful suggestions, thank you. I went back and reviewed discussions about the soda wash described by Chris Campbell. Does this flux to an extent it would result in sticking to a shelf if used on the bottom of a piece in a cone 6 firing?
And a similar question with underglazes as, in my experience, some flux to a certain degree. If using underglazes on the bottom/against the shelf should one be attentive to choosing those that fire to a matte finish?