An edible, hardenable coating composition containing microcrystalline cellulose and carrageenan and at least one of a strengthening polymer, a plasticizer, a surface active agent or a combination thereof. The coating composition of the present invention may be applied to pharmaceutical and veterinary solid dosage forms, confectionery, seeds, animal feed, fertilizers, pesticide tablets, and foods and provides an elegant prompt release coating which does not retard the release of active ingredients from the coated substrate.