Printing a lithograph of Le Mont Saint Michel, one of a series of drawings made in France on discontinued paper litho plates… The readymixed solution for printing them had gone mouldy, so after a consultation with Robin Smart (head lithography technician at the RCA) I developed this method which proved workable: –
150ml gum arabic/ 150ml tap water/ 4 drops lemon juice for sensitising the plate, using a soft cotton rag rather than a sponge, then rolling the plate with litho ink (experimenting with adding a bit of magnesium sulphate). Re-charging the roller 3 times per print. For the edition, leave the lemon juice/ citric acid out of the solution. The best prints are nos. 5-15 approximately. It is possible to obtain 20 pulls before the plate deteriorates, and the details start to fade.
Thanks Robin!