Preferred polymers include vinyl polymers such as polyvinyl chloride and polyvinyl alcohol, cellulosics such as methylcellulose and hydroxypropyl methylcellulose polymers, unsaturated polymers such as polybutadiene, inorganic polymers such as polysilicon (e.g. colloidal silicon dioxide), and emulsions of thermoplastic polymers dispersed by polymeric surfactant such as a polyoxyethylene.