Detailed description of simple semi-dry electrolytic method for etching metal plates. Extract from GREEN PRINTS by Cedric Green published by Ecotech Design, Sheffield, UK. - a handbook on new methods for non-toxic intaglio etching and metal plate printmaking, featuring the technique of Galv-Etch, a modern development of the 19th century electrolytic techniques of Electro-Etching and Galvanography, and introducing Fractint and other alternative methods for avoiding the use of solvents and chemicals harmful to health and to the environment.

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a semi-dry method for galv-etch

For certain purposes - for galv-etching a small portion of a large plate; for applying a particular texture over an area without using fractint (see later) or aquatint or other alternatives - I have developed a method that does not require immersion of the plate in the electrolyte, and therefore does not need a tray, grid, or vertical tank with cradles etc. The method is best suited as an alternative to open bite, but it can be used to etch needled lines or tint, and is proving to be rich in new possibilities. I have called this method "galv-on" as it expresses the way that it is done flat on a surface by forming a sandwich of electrolyte soaked felt and and other absorbant materials on top of the plate to be etched.


The area of the metal plate to be etched is prepared - masked with varnish or a stencil - then the plate laid face up on several sheets of blotting paper or newsprint on a flat level surface, with a thin flat strip of metal under a corner connected to the positive terminal of the power supply. Lay a thick pad of good quality well washed felt, soaked in the electrolyte, having allowed to drip dry for half a minute, over the whole area to be etched. Gently press the felt down all over with a small roller to squeeze out the air bubbles. Place a flat plate of the same metal as the plate over the felt area, connected to the negative terminal. Then place a block of wood or board on the cathode plate and weight it with something heavy until some of the electrolyte squeezes out of the edges of the felt. Turn on the current for longer than you would need to etch in a tray or tank, but the precise time required will have to be calculated by experiment as described in the next section.

Preparing a plate - pieces of blotting paper and felt laid over exposed areas of plate. Note the metal strip already taped to the back of the plate ready to be connected.

The current will pass through the electrolyte held in the felt and will etch a texture over the area which will depend on the quality and condition of the surface of the felt. The texture is usually more or less uneven but never uninteresting. To make the texture more even, several layers of clean thick blotting paper soaked in electrolyte can be placed between the surface of the plate and the felt, and trapped bubbles of air squeezed out with a roller. To reduce the unevenness still further, the felt/blotting paper can be moved a couple of times in between a series of short etches. Other porous materials can be placed next to the plate under the felt to produce different textures, like soft non-sized papers, fabrics etc. A paper with a strong printed image or with a design in a water resistant varnish, soaked in electrolyte, laid face down on the plate and backed with blotting paper will leave a negative image etched into the plate. I have experimented with etching through negative screened laser-printed photographs, soaked in electrolyte, and then rolled onto the plate which has been quickly wiped with acetone, with interesting results. But this cannot be considered yet as a viable method for photomechanical reproduction, although the effect produced has a quality that printmakers should find quite agreeable because of its imperfections and soft outlines and reversal of some tones. (TOP)

The sandwich of plate, dry blotting paper, tissue papers, felt etc. backed by the thick layer of soaked felt and then, the copper cathode plate and board being laid down to receive the weight, before being connected to the power supply.

galv-on collage

One way in which the semi-dry method can be used is to create a 'collage' of various cut and torn papers, thin felt, fabrics and materials over a masked area, backed up with the thick soaked felt. The different porosities and textures will offer different resistances to the current and will etch to different depths to reproduce the collage in different tones and textures. If the elements of the collage are not wetted first in electrolyte, then they will buckle as the electrolyte soaks down into them with unpredictable but sometimes very interesting effects. A mask or stencil made with a slightly porous material like thick cartridge paper, previously soaked in water (so that it does not buckle) will give a soft edge to the etched area. semi-dry galv-etching needled lines or tint (TOP)

Proof of plate produced by The Galv-On process illustrated above - Zinc plate proofed intaglio in black and over-printed in relief using the same plate in two colours.

etching needled lines or tint

The unevenness and texture that is inherent in the semi-dry method, when used to etch lines needled in a ground, or a uniform aquatint or fractint, will tend to show through slightly. But it can be minimised by using several sheets of good quality blotting paper well soaked in electrolyte under the felt layer. Divide the time required into 3 or 4 equal intervals and in between each, lift up and rotate or move the blotting paper and felt to even out the variations in strength of etch. Areas not etched at all are due to air bubbles which can be eliminated by using a small hard rubber roller on the back of each blotting paper layer. New felt must be very well washed in strong detergent to remove the natural oiliness in the wool. After a while the top of the felt will collect metal which has not stuck to the cathode, which has to be washed out. Pieces of blotting paper can be reused if they are clean, but as soon as they become discoloured, discard them. (TOP)

Detail of print produced using Galv-on semi-dry method - a mask of heavy soaked blotting paper forming the letter form over dry tissue paper which wrinkled and created bubbles which prevented areas from etching through. Proofed intaglio in black and overprinted in relief from the same plate in colours.

©: . Last altered on December 9, 2011