Abstract: The present invention provides moldable compositions that are capable of resisting slumping and cracking when allowed to dry and harden. Embodiments of the moldable composition comprise water, fillers including arrowroot and kaolin clay, at least one polar polymeric resin (e.g., polyvinyl alcohol), at least one thickening agent (e.g., ammonium pentaborate tetrahydrate), one or more pH adjusters (e.g., triethanolamine, sodium bicarbonate), a humectant (e.g., propylene glycol, glycerin), optionally at least one releasing agent (e.g., mineral oil), and optionally at least one additive.