• unique qualities of galv-etch
• galv-tone
• electrotypes
• relief by galv-plating lines

One of the features of the way galv-etch works is that it is sensitive to the surface it is biting - edges are bitten more quickly than the centre of flat planes, and irregularities like lines, texture, are enhanced, rather than etched out. So an area of open bite will be slightly deeper at the edges up against the stopout varnish or ground. Any lines in an area of open bite are retained, although broadened progressively. In a needled plate, closely spaced lines are bitten less deeply than isolated or widely spaced lines. Closely hatched areas never tend to be foul-bitten by the gradual amalgamation of the lines. But you have to be careful to stop out areas of widely spaced lines that you want to leave lightly bitten .(TOP)

galv-tone

Any texture, even the crystalline grain of the metal, is enhanced to give a fine grained matt surface which prints as a very fine tone. (.................) but I prefer to call it galv-tone, because it is more like a deep even plate tone (................). So the tones in any print can be subtly darkened, simply by stopping out the areas to be preserved, and giving a very short galv-etch.

A plate open bitten in stages after progressive stopping out will show a gradation of tones, the edges of which will be clearly defined by a line - the change of level. The tone at any level can be darkened by reversing the terminals for a time, which will deposit metal back onto the developing texture and around the edges of any ground or varnish. For this deposition to be rough enough the voltage and amperage must be high. This amplifies the crystalline effect of the bite and softens the hard lines around the areas of tone. The longer the time given to the reverse 'galv-plating' stage, the darker the tone, which will resemble the effect of 'carborundum'. A deep galv-plated area can be burnished or scraped and treated like a mezzo-tint.

Zinc alloy plates give a greater range of galv-tone than copper or steel. A series of overlapping areas of very shallow open bite will progressively darken the overlaps more noticeably than successively deeper layers. On copper, the galv-tone seems to be slightly darker if a very low voltage and current is used. The tone can be made even darker by allowing the electrolyte to dry and crystallize on the open bite area and leaving it to oxidize for a while before continuing with the open bite. After the first galv-tone, you can draw over the matte finish with wax crayon or litho pencil, which will resist further action and show up as lighter lines or shading. Don't use zinc plates or electrodes in copper sulphate, because zinc tends to precipitate copper ions from the solution and weaken it (see the chemistry of Bordeaux Etch).

To create a darker textured tone without using fractint or aquatint, see the pages on the GALV-ON semi-dry method.(TOP) 

Example of galv-tone on a copper plate.

electrotypes

Another way of using relief is in the way galvanoplasty was originally used, by creating a new plate by depositing copper over three-dimensional modelled relief made with wax, glue, card, tissue paper, or any other means from which you couldn't normally print. The relief is then coated with graphite which provides an electrically conducting layer, and connected to the cathode (-ve) and 'plated' with copper. The current required is about 0.5 amps/100 sq.cms. or 0.03 amps/sq.inch - and the coat should be quite thick, at least 1 mm. which take some hours (up to 24). Then the new plate, which is the negative of the original relief, is parted from it and then backed with a filler of epoxy resin (often sold as 'liquid metal') to stop it being flattened in the press. It can be printed in relief, intaglio or a combination, using different viscosity inks (see section on proofing). If you want to reproduce the relief of the original plate rather as a positive, then you will have to make a mould of your original with 'vinamold' or similar moulding material, which can be coated with graphite before depositing the metal. Plaster of Paris was used for the mould in the past. Before making the mould, the original should be dusted with French chalk or any substitute (not containing asbestos) to aid separation. Then dust the graphite powder onto the mould with a brush. If it does not stick, try breathing on the mould to make it slightly humid and then the graphite should stick to most materials. If that does not work on some materials try a very thin coating of liquid silicone furniture wax before brushing on the graphite. The copper 'electrotype' produced is capable of reproducing the finest detail and even brush strokes of varnish or of silicone wax will show when proofed as an intaglio. If a silver-plated sheet of copper is painted with layers of thick varnish which dries to a slightly rough textured surface, then a negative electrotype of it will reproduce it quite closely, the proof showing darker tones where the varnish is thickest. This is the technique described in the nineteenth century as 'Electro-tint' (7) (see also Appendix A) . Another developer of this technique is Ole Larsen in Sweden, which he has called "Polytype" (13). (TOP)

relief by galv-plating lines  

If instead of biting into a needled grounded plate, you reverse the terminals and make your plate the cathode, metal will be deposited into the lines, and built up in relief. If the projection is very fine, no more than one would get with a drypoint burr, then the plate will print rather like a drypoint, only last longer because the projecting metal is less fragile than a burr.

But more interesting to me than just reproducing the effect of a traditional method, is the completely original effect of applying an open bite over a plate with fine relief lines produced by the process described above. The results are unique to this process, and give a print with very subtle tones and grain, in which the raised lines act like a burr in the tonal areas, and if they are lightly burnished, print as fine white lines, an effect quite unobtainable in traditional intaglio printing. The voltage and current need to be high, and the lines very clean, so it is a good idea to immerse the plate in a vinegar and salt solution first to clean out any grease. Another solution is to galv-etch the lines first very slightly, before reversing the terminals, which establishes an electrically 'clean' line in which to deposit metal. But if the line is deep, then the burr will be doubled, building up on both edges of every line, a phenomenon which can be exploited for expressive effect. (TOP)