Below some details about lith prints (quoted from the World of Lith Printing, by Tim Rudman)
"Lith printing is a simple but ‘different’ Black & White printing technique, using ‘ordinary’ negatives, a suitable black & white paper and Lith developer – from which the process gets its name.
...... The results can be immensely diverse in different hands, according to the choice of materials and the techniques used. Lith prints possess unique characteristics and properties and these can be exploited to get different effects, so it is a flexible, adaptable and therefore very creative way of printing. It is all to do with grain size…
What drives this process and allows it to be so creative and variable is a property of lith developers known as ‘infectious development’. Put simply this means that as tones get darker they develop faster, so they get even darker, develop even faster, get darker still, and so on. This results from a chemical chain reaction and consequently development of the darker tones in the print accelerates exponentially, leaving the lighter tones lagging way behind.
The significance of this is that during development the silver grains in the paper’s emulsion grow steadily larger and in doing so, they change in appearance in a number of ways:
The fine grains of early development are generally super-warmtoned, soft and creamy in texture, grainless in appearance and low in contrast. The large grains of late development are colder in tone, coarse in texture, very grainy in appearance and high in contrast. In lith printing, this can be exploited by stopping the development when the balance of large and small grains (in shadows and highlights respectively) is as you want it – l the ‘snatch point’.
There is no right or wrong choice for this moment. It might be when the print it is predominantly fine-grained (warm, creamy, grainless, low contrast) or later in development when predominantly large-grained (cold, coarse, grainy and contrasty) – or it might be with a balance of small-grain light tones and large-grain dark tones (warm, soft and grainless highlights with cold, grainy high-contrast shadows). The choice of snatch point has a profound effect."
also http://en.wikipedia.org/wiki/Lith-Print
