|Extending the etching
I prefer a solution of pure bees wax, drops of mastic varn ish and bitumen dissolved in a 60/40 solution of pure turpentine and ch- loroform. This solution dries quickly and leaves a dark thin elastic film quite sensitive to the etch ing point. Smoking the plate is to be avoided, as it both heats the copper and covers defects in the ground. I have found that if you avoid heating the crude copper it is possible to print well over 500 copies so the limitation of the edition becomes ethical rather than practical.
|Etching the plate.
I use a dentists drill honed to a fine point. There are many other fine steel points available so its a question of choice or habit.
The plate can be many materials , crude copper, micro-zinc, brass, iron or steel. Each material reacts in a particular way to the acid so it should be chosen with the end result in mind.
|The first bite
Each material has a series of acids which function in a different way so again the acid should be chosen with the end result in mind. In this case I used ferric chloride in a weak solution so the etch was about an hour long. In all cases its better to do this outside or in a well ventilated cool place. I use a double basin to control the temperature of the acid so the bite is as controlled as possible