The Danish State Archives was established in the 1880s, the Zealand Provincial Archives Workshop in 1892. Their working techniques were taken from those in use in other European archives. Where possible, parchment was used for repair, or else Japanese tissue, with office glue, bookbinders' glue or flour paste as adhesive. These repairs are now virtually impossible to remove without damaging the parchment. The methods current in the 1920s for reviving irongall inks were not introduced until 1969 and fortunately only then in very special cases. In Germany, in the 1920s, paste, gelatine and cellit with silk tulle were used for parchment repair. In France parchment bindings were cleaned with alum solution, restored with parchment (paste adhesive), oiled (almond oil) and polished. Starch paste and formalin have been used at the Danish State Archives, but formalin was abandoned in 1969. Since the 1940s, Japanese tissue has been used for repairing.