What varnish or sealant do you use for air dry clay?

I myself use the same one for polymer as for air dry clay which is Fimo gloss varnish. Mini mo wrote a great quide on different varnishes, it's a great link if you have trouble deciding which varnish/sealant to use. http://www.sweetandtiny.net/2011/04/beginners-help-varnish-or-not-to.html