Nowy wariant techniki dublowania na stole próżniowym

A new variant of plying-up paintings with a high delicate texture proposed by G. A. Berger (Maltechnik— Restauro, I (1980, p. 50— 6 6 ) and which was to eliminate the pressure of foil upon a painting layer has been tested in practice and employed in the Department of the Conservation of Paintings and Polychromed Sculptures in the Copernicus University of Toruń. Instead of Beva 371 recommended by Berger, a water binder (50 per cent water emulsion of Osacryl with 4 per cent methylcellulose as 1 :2) was used giving a tight airproof coat on the back of the plyed-up painting, which made it possible to produce underpressure between the back of the painting and the top of the table. In this lies a difference between that method and a traditional one; moreover, it permits for the plying-up without covering the whole facing of the painting with foil. An additional advantage of the described technique is the possibility to dry up the painting completely during the treatment under a continuous effect of underpressure and increased temperature, which reduces greatly a risk involved in every traditional plying-up on a water binder. This offers also a possiblity to avoid numerous inconveniences of drying the painting with tissue paper under high pressure. The method has been employed in practice to ply up the 18 th-century picture of „Madonna with the Child” .