Aquatint spray resist Lascaux

Composition:
Based on acrylic copolymer

Lascaux Aquatint spray resist has been specially designed as part of the acrylic-resist etching system. This new-generation acid resist is used to create controllable tonal effects. The effects which can be generated by using this resist are comparable to those offered by traditional aquatint methods.

Properties:
This blue coloured resist is water-soluble and ready to use. It can be applied to all metals (unbitten or previously etched plates) using a simple diffuser/airbrush/spray gun. The sprayed dots of resist are designed to maintain their individual integrity and to dry rapidly on the plate surface. It is compatible with the other Lascaux resists and photopolymer films.

Directions:
Plates should be prepared, grained, degreased and dried before the Aquatint spray resist is applied (follow the detailed information provided in the technical sheet for Lascaux Hard resist).

Drying the resist:
The plate can be laid flat to dry naturally or dried with a warm air fan in a horizontal drying cabinet. The resist becomes touch dry quickly and when it is fully dry the plate may be etched.

Etching:
Plates should etched following the detailed information provided in the technical sheet for Lascaux Hard resist.

Working the plate further:
The surface may be lightly wet-sanded or polished to enhance the contrast and clarity before proofing. The plate may also be worked further using subtractive or additive methods.

Equipment:
A single action, external mix, bottom feed spray gun such is inexpensive and ideal. Single action, bottom feed, internal mix airbrush can be used for greater control and if a finer dot is required. The airbrush may be powered by a simple aerosol canister or by a ‘silent’ airbrush compressor. Spraying should be carried out in an airbrush spray booth or work bay fitted with a vapour extraction fan. A mask (suitable for aqueous sprays) should be worn and the extraction fan must be operating when spraying is in progress. Plates should be sprayed in an upright position. A board with a simple shelf (10 cm from the bottom) made from a row of 12 small headless nails partly driven into the wood makes a useful support. At the top of the board a metal strip can be attached to hold magnets which can be used to trap a backing sheet of clean newsprint.

Spraying technique and theory:
Practise on clean newsprint paper in order to develop spraying skills and consider the likely results (see the different image-making methods below). The density of the aquatint is determined by the distance between the airbrush and the plate: the greater the distance, the further apart the dots. Adjust the tool to deliver either a fine or coarse mist. Remember that the more the plate is covered with dots of resist, the smaller the surface area of metal the mordant can etch, and the lighter the resulting printed tone. Beware of covering the plate too densely as little or no etching will be able to take place. Areas which are not sprayed at all will etch as open-bite. You should consider whether you want to spray a light mist on these areas (to make them dark) or stop them out with Lascaux Stop-out resist (to preserve them as highlights). When you are ready to spray the plate, place a clean sheet of newsprint on the board, then position the plate upright on the shelf, leaning back slightly against the paper-covered board. Test the airbrush on the newsprint, away from the plate, before spraying the plate. Keep a sample of the sprayed newsprint as a learning aid. When the plate is dry examine the dots of resist and check that there are spaces of uncovered metal between them before etching the plate.

Uniform aquatint:
For a uniform aquatint, practise coating the plate using parallel horizontal bands, starting at the top and spraying off the edge of the plate for a minimumum of 10 cm before changing direction (serpentine shape) until the plate is covered. If you decide a second coat is needed, rotate the plate through 90°, allow the first coat to dry for a minute or two, then repeat the process. Deeper tones and more complex results can be achieved by repeating the aquatint (or application of other resists) and the etching process several times.

Modulated aquatint:
The airbrush can be used to paint with, creating a modulated aquatint which varies in density across the plate surface. Soft effects can be created by painting an image on the plate with water and then spraying the plate. The plate can be sprayed in a horizontal position if necessary.

Stencilling methods:
Shapes can be made by sticking slightly dampened lightweight paper stencils to the surface of the plate before spraying. These are lifted away after spraying to reveal exposed metal. Painted marks may be made on the plate using Lascaux Lift solution. This is allowed to dry before being sprayed over, dried and removed, leaving exposed metal in the shape of the Lascaux Lift solution marks (see data sheet for full information). When a modulated or uniform aquatint is applied to these media, a background tone will print. If a white background is required, continue to spray the aquatint in layers, allowing each to dry for 1-2 minutes between coverings. This will result in a continuous film of resist which will prevent the plate etching where the resist has bonded with the plate surface.

Removal of resist from airbrush:
Lascaux Aquatint Resist is water-soluble and can be cleaned from tools, plates and surfaces with warm soapy water. As the resist dries quickly, tools should be cleaned immediately after use. Follow the user instructions for cleaning the airbrush. Remove the reservoir bottle from the airbrush after use, rinse and fill this with clean water, and spray the water onto newspaper until the tube and spray are completely clear. Repeat until the airbrush is clean.

Drying the resist:
The plate can be laid flat to dry naturally or dried with a warm air fan in a horizontal drying cabinet. The resist becomes touch dry quickly and when it is fully dry it is ready to etch.

Etching:
The plate can be etched in a variety of mordants such as solutions of ferric chloride (for copper and brass) or copper sulphate mixtures (for steel, zinc and aluminium). Correct facilities and safety precautions should be used when etching. Plates should initially be flash bitten (etched for a few minutes) to reveal the areas of metal which are etching. Areas which should be etching but still look shiny and bright may be contaminated with a greasy fingerprint and will need to be degreased with household dishwashing liquid. If flash biting does not reveal any problems normal biting can commence. However if any other resists (stopping-out) are to be applied, the plate should first be rinsed, de-oxidized with a solution of salt and household vinegar, rinsed and dried. After etching, plates should be rinsed and deoxidised before removing the resist prior to proofing.

Resist removal:
The resist is water-soluble and can be cleaned from brushes, tools, palettes, plates and surfaces with warm soapy water before it dries. Dried resist can be removed with Lascaux Remover (follow the information provided in the technical sheet for Lascaux Hard resist or Lascaux Remover).

Working the plate further:
The surface may be lightly wet-sanded or polished to enhance the contrast and clarity before proofing. The plate may also be worked further using subtractive or additive methods.

More information
This product has been developed in collaboration with the printmakers Robert Adam and Carol Robertson who have been researching and teaching safer printmaking methods since 1990.