Aquarelle, 20 x 15 cm, 1981
Carpenters, in order to establish the specification for the structure they imagine, which do not yet exist, such as the assembly of uprights for a frame, perfected a system which Monge later integrated into his descriptive geometry.
The working drawing describes an object which, in fact, appears only to the specialist, the carpenter. For everyone else, the material appearance of the object describes remains invisible. However these drawings present an interest which goes beyond the concept for constructing a framework, in that they offer a view of one spacial dimension transfered to another: they present somehow a photograph of this transfer, back and forth, between two states, one in the a drawing and one in a volume. The exchange between one spacial status and the other is recorded by the lines forming the orthographic projection in a succession of rotations and intersections of the points, lines and planes involved.
Is the invisibility of the object paradoxical — if we consider that this procedure will result in the construction of this object with the greatest precision and without the last ambiguity? The object remain invisible but it project a precise shadow: not the shadow cast on the drawings, but a shadow of projections, a shadow which unfold in the intermediary space between the object and the orthographic projection, or even better: the structure of this shadow.