Once the original sculpture of the woodstock has been finished, it is given to the founder, who, after moulding it, makes wax casts identical to the original, with which he can produce his bronze sculptures.
A lot of chiselling work is necessary after it has been released from the mould, and it is the success of the patina which will give it life.
8 copies of the bronze are produced, plus 4 artist's proofs.
The lithographic technique discovered in 1796 by Aloys Senefelder is currently used by only a very few artists.
This old printing technique requires long, rigourous, precise and methodical work.
The principle of lithography (from the Greek lithos : stone, graphein : to write) consists of drawing on limestone a pattern which will be reproduced on paper. This limestone, called Solenhofen stone, absorbs any form of grease, is hand-grained and perfectly smooth, and is drawn on by the artist, who uses lithographic pencils and ink.
Once the work has been completed, a solution of acacia gum and nitric acid is poured onto the whole surface of the stone. This mixture attacks the parts of the stone which are untouched, and unprotected by the drawing.
The picture is then removed from the stone using turpentine oil, and inked up manually with a roller to reveal the drawing again.
The stone is placed on the carriage of the hand press, which enables multiple copies to be made.
Once the printing is complete, the stone is grained – ie sanded down using water and Fontainebleau sand – and is ready for a new drawing. Each phase – drawing, preparing the stone, printing and graining – is carried out by Pierre Roussia in his studio.
Two techniques are used:
1. The first technique consists of drawing as many different stones as there are colours, and printing one colour after another, from the lightest to the darkest, a technique which requires great precision in placement.
2. The second consists of illuminating by hand each lithography, which has already been printed in black and white, taking care to prepare all the blends of colour.