Printing Methods

Etching

Intaglio refers to a design carved or etched into a surface. Intaglio printing refers to a plate where the design is in some way hollowed into the plate. Ink is wiped into the hollows, the surplus wiped off; paper is then placed over the plate and when rolled through a press the ink will be transferred to the paper.

Etching is different to other intaglio techniques; marks are made by corroding a metal plate with a mordant.

Some of the earliest examples of etching are found on suits of armour. Originally decorated with hand engraved lines, armourers found that etching crests, coats of arms and other decoration was quicker and more profitable than engraving. They soon began to make sample ‘look books’ by filling pigment into the lines and pressing damp paper over the marks thus making a printed image. The earliest known signed print on paper was made by Urs Graf in 1513. It did not take long before the commercial possibilities of the method were recognised. By the middle of the nineteenth century there were over 150 intaglio publishers in London producing all manner of drawings, versions of famous pictures and illustrations. A whole new world of art, previously exclusive to the very rich was opened up.

Traditionally the metals used are zinc, copper or steel. Plates are prepared for etching, the edges of the metal are bevelled to a 45º angle, the surface is completely degreased, a ground is then applied and the back of the plate protected with sticky back plastic. Once the ground is dried you can draw into it using an etching needle. Anything with a blunt point can serve as an etching tool, the idea being to remove the ground where you wish the mordant to bite into the metal. It is best not to scratch the actual metal – this makes adjustments to your drawing easier. Errors can be corrected by covering with a stop-out fluid and re-drawing when this is dry. When the image is completed check over the plate to stop-out any unwanted lines, holes in the ground and protect the bevelled edges with stop out. The plate is then etched in a mordant.

The ground is removed, plate inked and wiped and then printed.

Mordants
10% solution of nitric acid line biting
20% solution of nitric acid aquatint
Edinburgh Etch (Ferric chloride with citric acid)
Saline solution – a less toxic method used with either aluminium or zinc - this is offered for etching courses at The Print Shed and can be safely used without fume extraction

ETCHING PROCESSES SHOULD BE USED BY EXPERIENCED PRINTMAKERS OR UNDER THE SUPERVISION OF AN EXPERIENCED PRINTER

FUMES ARE GIVEN OFF DURING THE ETCHING PROCESS AND IT IS VITAL THAT ADEQUATE FUME EXTRACTION IS IN PLACE.

ALWAYS ADD ACID TO WATER
NEVER WATER TO ACID