TECHNOLOGY FOCUS - CERAMICS AND GLASS - Preferred Component: The ceramic powder comprises alumina, zirconia, silica, titania, silicon nitride, silicon carbide and/or aluminum nitride.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The water soluble cross-linking agent precursor is temperature activated. The cross-linking agent precursor forms a multifunctional aldehyde upon temperature increase. The cross-linking agent precursor forms a dialdehyde upon temperature increase. The optional further components comprise binders, dispersants, chelating agents, surfactants, defoaming and/or wetting agents, salts, coloring agents, buffers, acids and/or alkali. Preferred Material: The cross-linking agent precursor is 2,5-dimethoxy-2,5-dihydrofuran (DHF).    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The method comprises removing from the substrate a flexible gelled material obtained following the third step; and drying the flexible gelled material. Preferred Component: The polymer is polymers having amide, amine, carboxylic acid and/or hydroxyl functionalities. The polymer is chitosan, polyvinyl alcohol, gelatin, poly(allyl)amine, polyethylenimine, chitin, polyacrylic acid, polyvinylacrylate, polyacrylate, polyacrylamide, pectin, and/or xanthan gum. The slurry without added DHF had not set at all. It was allowed to dry for one day at room temperature. A tape was formed which cracked severely when peeled from the substrate. The result demonstrated that, in comparison to conventional tape casting, the application of cross-linking, for the production of ceramic tapes/sheets, produced superior products.    EXAMPLE - A 15 wt % solution of Celvol 203S polyvinyl alcohol was prepared by stirring the polymer in de-ionized cold water for a short period of time. To 54 g of Celvol 203S solution was added 6 g of polyethyleneglycol. The mixture was stirred to dissolve the solid. Aqueous hydrochloric acid (1.97 ml) was then added to the solution with stirring. A 25 ml aliquot of acidified polymer solution was then transferred into a sample bottle and 81.2 g of alpha-alumina powder was mixed in manually. The suspension, in sealed sample bottle, was then sonicated in bath and tumble mixed overnight to give homogeneous slurry. Glycerol (5.5 ml) and 1-octanol (0.17 ml) were then added to the slurry followed by further tumble mixing. The slurry was then transferred to a flask and de-gassed. A small amount of slurry, without added cross-linker, was spread over silicon coated tape to give an slurry thickness of 0.5 mm. The tape was covered with Perspex to avoid solvent evaporation. To the remaining slurry in the flask (67.2 g) was added DHF (0.4 ml). The mixture was stirred and then cast on silicon coated tape and also on plain ceramic tile in an identical manner as previously described. The cast slurry was covered with Perspex to avoid solvent evaporation. After standing overnight at room temperature, the Perspex covers were removed from all of the tapes. The tapes to which DHF was added had undergone a significant amount of syneresis indicating that cross-linking had occurred. They were flexible and strong and were peeled from substrate while completely wet without tearing or permanent deformation. Upon subsequent drying, a strong and flexible tape was produced which could be repeatedly rolled and unrolled without permanent warping or cracking.