Ceramic decals have been used for decades to enhance the value of ceramic products. Hand painting using colored glazes (enamels) is more expensive and the production rates are much slower. However, the ware may be more valuble than decaled ware. Decals can be produced by silk screening or by lithography, the former being more expensive. Silk screening allows heavier color deposition. The process to make a decal is to add colored oxides to drying solvents and binders to form an ink. Low-melting frits may be incorporated in the inks to assure that the decal will sink into the glaze on firing. The colors are printed or silk screened each color individually onto a special decal paper. A cover coat is applied to the printed decal sheet before the final drying of the decal sheets. Go to http://www.beldecal.com/create.cfm to learn the actual details of the process. (Its a pretty stinky process. Take a sniff while you are reading.) Several color separations are used. For fine china, seven passes through the silk screening process are often required to obtain the color detail desired. Three-color separations are okay for many other products. Now Im going to send you away again. Richard Wasowski, a long-time friend of mine, (dont call him Dick, please) wrote an article for Ceramic Industry Magazine (I was once the editor of this magazine) on the digital process for decaling. This newer process will probably someday completely replace the older methods. Go to http://www.ceramicindustry.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2710,80851,00.html. Oh, you came back again! Decals are typically printed on large sheets. A worker cuts the sheets into individual decals and places them into water (usually with a wetting agent) where they soak until another worker slides the decal off the paper and places it on the ceramic ware. He or she then squeegees out the water making sure that the decal is placed correctly on the ware and that there are no bubbles trapped under the decal. The decal is dried, usually in open air, and then fired on a 1-3 hour cycle. Decaling is a low-loss process. If there is a flaw in the decal after firing the ware usually must be scrapped. It may not be profitable to continue processing a piece of ware that you know will be sold as seconds. Now days, enamel and or precious metal are often incorporated in decals. This saves two extra firings if both enamel and precious metal are added. If precious metal is added separately, it still saves one firing. This can be very cost effective. For one thing, you are not wasting gold or enamel nor do you have to worry so much about environmental considerations. The End Ceramic defects, decals, decaling, decalcomania, decorating ceramics, color separation |