What Finish??

I have done a search but have not really found an answer to my question.

A potter has asked me to turn some small saucers for a mug set they are making and my concern is what finish would be suitable so as to be resistant to liquid spills? I thinking of a satin finish or similar.:?

Rustins Plastic Coating, you can have a satin finish through to a glass like gloss, it is impervious to water spills alcohol spills etc, can be hand washed with damp cloth