Experimenting: "Open Bite" Etching

Experimenting: "Open Bite" Etching

I have used aluminium on a number of occasions for dry point etching. It is soft enough to be able to scratch into the surface relatively easily. However, last year, I used aluminium in an experiment for etching and aquatint. The disadvantage is that aluminium does not produce a "white" finish and sometimes has some imperfections. However, I find that images produced from aluminium often have a lot of character.

I was going to repeat this experiment for an image I wanted to create of a creek at South Ferriby, where I had seen some old boats moored up to a rickety set of ancient landing stages, and which were exposed due to low tide. The mud around the boats was also an interesting feature.

However, talking to a colleague I learned that aluminium, can also be used for an "open bite" process, which eliminates the use of the aquatint box process. Tone is produced by "stopping out" the tonal areas, the lightest tone first, by immersing the aluminium plate direct into a bath of copper sulphate to etch direct into the tonal areas. I thought that it would be a good idea to experiment with this process and see what the outcome would be.

Process

I applied a hard ground to my piece of aluminium and then used my dry point tool to scratch my image into the surface. I then plunged the plate into the bath of copper sulphate for 20 minutes for the initial etching. This produced a line drawing, however, the image was very poor, possibly due to my not scratching hard enough into the hard ground, the imperfections of the aluminium, or that I had not left it long enough in the copper sulphate.

 

(1) Initial Line Etching

Anyway, I felt that the image was good enough for me to proceed to the next stage. I considered that I could use the process of adding tone to try and enhance the image.

I used "stop out" varnish to highlight the key areas where the light was falling, and then immersed the plate back in the copper sulphate. I then repeated the process to create a mid tone, and the darkest areas, leaving the plate in to edge for the final time for about 30 minutes.

Outcome

(2) Tone Added using the "Open Bite" method

When I printed the image I was surprised at what a good print I had created using this process. This outcome was especially pleasing considering how "bad" the initial print had turned out. The "open bite" process had successfully added not only tone, but also clarified the image, which had been very poor to begin with.

Future Use

I will use this method again where I want to create tone and character on an aluminium plate. It proved that I do not have to use the aquatint box to do this. The process will be useful to create good tonal effects, and also to help create "mood". It makes a line drawing more interesting and challenging. I will still use zinc for more "formal" or detailed results, and where I want to create really white areas.