Solarplate and glass
This technique was developed by Master printmaker, Dan Welden, for working with solarplate. Solarplate is a waterwashable, steel-backed, light-sensitive polymer plate made by Toray. Although designed for commercial letterpress printing, Welden adapted the plate for intaglio printmaking in the late 1970s, while searching for a simpler alternative to etching. As a tough, resilient plate with a wide latitude for exposure, it is ideal for exposing in the sun, hence the name. Images must always be prepared on a transparent or translucent material and one interesting way of working is to draw on grained or sand-blasted glass. Solarplate tends to capture the quality of a drawing and intaglio prints created from images prepared on such a glass resemble lithographs and are enriched by the intaglio effect.

Preparing, graining, blasting
To make a plate you need a solarplate, a contact frame, water, a natural bristled scrubbing brush, some talcum powder and a lint-free towel. Cover a tin piece of board with a piece of foam 6 mm (1/4 in) to make the base of a simple contact frame and use a slab of plate glass of the same size clipped to the base with clamps or bulldog clips as a weighted cover. To ensure good contact, make the contact frame approximately 2.5 to 5 cm (1 to 2 in) larger than the image, and make sure the solarplate is cut without warping its steel backing. Access to a sharp guillotine or a sturdy paper trimmer is very useful. Always use plate glass for graining since thinner glass (3 mm) may break when you draw on it. Plate glass can be bought cheaply at garage sales, but rough edges should be polished or sealed wit duct tape so you do not cut your hands. Then, to obtain a textured surface, either take the glass along to a glazier for sand-blasting or grain it yourself. Prints created from sand-blasted glass have more contrast, while a grained surface is very sensitive and will capture fine marks, washes and a great range of tonal effects.

Graining glass
Graining glass is very similar to graining a lithographic stone. You require water, carborundum and either a levigator, a glass muller, a small, thick piece of plate glass or a lithography stone. Put on some protective clothing, eye goggles and gloves. Soak an old towel with water, spread it on a flat working surface and place the glass on the towel; the dampened towel will prevent the glass from slipping during the graining process. Wet die glass slab with water and sprinkle some carborundum evenly over the surface.
The carborundum can vary from a coarse grade of 80, up to very fine, 220; the finer the carborundum the finer the toothed surface and the subtler the drawing possible.
Place the levigator on the glass and move it in a circular fashion, slowly rotating the disc with the abrasive and water, graining the surface as evenly as possible. If done correctly, the levigator should have a smooth, gliding action.
A glass muller is a lighter safer tool but will still create a beautiful crisp, finely toothed surface. A flat stone or piece of plate glass works just as well but, as you grain, move the stone or glass in a figure eight. One you have a finely grained surface, rinse off the carborundum, allow the glass to dry and start working on it.

Drawing the image
Experiment by drawing with pencils, graphite sticks, charcoal, black pastels, litho crayons, litho pencils, oil sticks, or any other opaque materials to produce richly textured marks. Try a variety of felt tip pens, or brush on tusche. You can use India ink washes, applying ink to only very finely finished grained glass otherwise it will bleed. Another approach is to roll a water-based or oil-based ink on to the glass and inscribe or work with brushes, adding and removing ink with a variety of tools and textures until your image is ready for exposing.

Double exposure
To obtain the best results a double exposure is recommended: first presensitising the solarplate with a random dot screen and then performing a second exposure with the grained glass image. It is also best to make and print test strips of solarplate first before exposing the image to an entire plate.
Remove the protective cover film from the solarplate and lightly dust the polymer with talc; this helps protect the screen and the drawing. Place the screen on the plate with the semi matt emulsion side against the polymer and clip together in a contact frame. Expose in the midday summer sun for 1 min 45 secs. Move indoors and remove the screen from the plate. Place the grained glass with the drawn image flush against die surface of the polymer, clip together in the contact frame and expose again for 1 min 45 secs. (When it is cloudy or at other times of the year when UV light is less intense you need to increase exposure times). Go back indoors, remove the glass and develop the plate.

Developing and printing
Put on rubber gloves and a waterproof apron and pour some tap water (25°C) on the solarplate and scrub, with the natural bristled brush, evenly all over for about a minute. Occasionally examine the surface of the polymer and you will see lines and grooves forming, corresponding to the marks of your drawing, while the rest of the polymer has hardened in the sunlight. Rinse the plate, blot dry with an old towel and put in the sun for five minutes for a final hardening. The plate is now ready for printing. Without using a hot plate, ink up as for an etched metal plate with an ink of fairly loose consistency and print under pressure with slightly dampened paper. It is easy to reuse the grained glass by washing off the old image and lightly re-graining the surface to remove any final traces.

Double or single exposure
Pre-sensitising the polymer with the random dot screen will capture much of the tonal range of an image and preserve the quality of drawn marks, washes and fine brushstrokes. It allows the creation of extensive areas of black in a print and overcomes the problems of deep grooves and open bite which can lead to ink bleeding during printing. Dan Welden used a double exposure for his image to retain areas of black. However you can expose the image without pre-sensitising the plate - Terry Elkins' image Shipwreck, delicately drawn with ordinary pencils, required only a single exposure.

Pros and cons
Solarplate printmaking appears safer than traditional etching and lithography, largely because no acids or hazardous grounds are used, but also it is a very fast process taking a matter of minutes, thus minimizing exposure to polymer chemicals during platemaking. However, government safety consultants' advice states that very little is known about photopolymers or their health risks. The flexibility of solarplate offers artists diverse ways of working; it not only captures the quality of a drawing, you can use many kinds of image - photocopies, found objects, computergenerated imagery or photographs.

Working on grained glass along with many other useful techniques will be described in a new book about solarplate printmaking by Dan Welden and Pauline Muir. A publication date will be announced soon.