One of the most frequently asked question on the polymer clay message boards is “How do I seal my polymer clay pieces?” Except for a few instances, for example: protecting the surface of a photo transfer or ensuring that a mica powder that has been applied to the surface doesn’t abrade there is absolutely no reason to apply a sealant to the surface of the clay.
I would imagine that you wouldn’t consider putting five coats of spar boat deck varnish onto an antique rosewood table…so why would you even consider putting Flecto Varathane or Future Floor polish onto your polymer clay creations? No matter how many coats that are applied, polymer clay will never look like glass- not to mention the propensity of these varnishes to glop, drip, bubble and drool! I’ve yet to see a piece that I felt was enhanced by the use of one of these varnishes and sometimes the glare makes it nearly impossible to see the beauty of the underlying surface.
When a piece of polymer clay jewelry has been worn a number of times it begins to develop a lovely patina from the body oils of the wearer. Other alternatives are to sand and buff your pieces to a high gloss, apply a light coat of Golden Acrylic Matt UV protectant or a light coat of archival wax (such as the Renaissance Wax book restorers use).