I want to make markers for my herb garden using polymer clay. I plan to make disks that imitate terra cotta, stamp each with the name of the herb, make a hanging hole in the top, and hang each from a metal stake that has a crook at the top.

Poylmer clay artists -- has anyone made articles for outside use like birdhouses, flower pots or other garden ornaments? Do I need to use a protective varnish or lacquer? Will the colors fade? Will they deteriorate in time?

Thanks for any advice you can give me.