Page 40 - Studio International - June 1966

At all times a balance had to be found between fidelity to Duchamp's thought, In other instances it was possible to speed up Duchamp's methods: the Oculist
and to the facts of the original. It would have been irrelevant to have used a Witnesses, for example, seen here in a reverse view to the left of the cones, are
cannon to make a new grouping of shots; but the method of colouration of silvered on to the glass. Duchamp had drawn them by laboriously scraping away
certain areas by controlled accumulation of dust was adhered to faithfully. the silvering. Richard Hamilton called in a cartographer from the University
Geography Department and with his help prepared a drawing for a silk screen of
the Witnesses with which he printed a resist in their image on to the silvering.
The unwanted silvering was then etched away, giving a far less laborious and as
brilliant result. Duchamp applauded these innovations, and has in some
instances suggested changes from original materials.
Below. Lower half of Glass, lead wire drawing, reverse view.