You start by preparing a metal plate (a sheet of metal). The most traditional material is copper, but now zinc and steel are widely used. Nicola uses zinc, which is a soft metal. To prepare a plate, the surface has to be polished, and the sides and corners bevelled using a file. This is to make sure that the plate does not cut through the paper on which it is printed.
There are several process to create a line image –
• Hard ground – this is a wax layer (acid resistant) that is applied to the plate. To get a more even layer and to darken the wax, it is ‘smoked’. The etcher can then create a line drawing by drawing through the wax to reveal the plate using a metal point. This can be a needle, but there are also etching needles which is like a pen, but with a metal point.
• Soft ground – this is a stickier ground and will produce a softer line. For soft ground the etcher will generally put a piece of paper over the plate with the ground on it and draw an image with a pencil.
• Dry Point – this does not involve acid, but using a sharp point to make a deep scratch in the zinc plate directly.
All of these processes can be used on a single plate. You normally carry these out with hard ground first, then soft ground and finally dry point.
After creating the image the plate is put into acid which bites into the plate producing a groove which will retain ink and therefore create the print. With steel you can clear a large area of metal and it will bite rough in the acid and retain ink. With copper and zinc large area of metal will bite smooth and therefore not retain ink. The process of aquatint creates shading on the plate.
To make an aquatint you need to put a dusting of resin onto the plate. This is done in an aquatint box. The resin particles are then heated onto the plate so that they stick. The resin particles are acid resistant, so that the area between the resin will be bitten by the acid leaving small grooves that will retain ink. The longer the plate is in the acid the deeper the acid will bite and the more ink will be retained leading to a darker shade.
The process of creating an aquatint takes several stages. First the areas that will remain white are covered by an acid resistant varnish or ink. The plate will then be left in the acid for a short time and removed, washing off any remaining acid. The areas that will remain pale are then covered and the plate is returned to the acid again. This process is repeated to get the desired shades onto the plate. The time the plate is in the acid, depends upon the strength o f the acid and shade that is desires. The resin will only be resistant to acid for a limited time in the acid, so the aquatint needs to be planned to get the desired effect.