Cotton is totally fine at the low baking temps required for polymer clays (any natural fabric or substance, actually), and even some synthetic things are fine too (like polyester stuffing). You might want to check out some of the options for supporting polymer clay figures and objects while baking on this page of my site though for more ideas and for details: http://glassattic.com/polymer/baking.htm …click on the category called SUPPORT DURING BAKING HTH, Diane B.