Assis (primer)
Assis (from Latin assis 'floorboard'; also axis 'floorboard, axis') is a primer used in the late Gothic period for wooden sculptures and book pages.
An Assis could consist of a wide variety of components. The Liber illuministarum has around a hundred different recipes. The main filler ingredient was mostly chalk or plaster of paris , but lime from mussel shells , clay and kieselguhr are also used. The filler was almost always colored with color pigments or boluses . The binding agents used were mainly egg white , various gum resins and glue from isinglass or similar. Additives could be vinegar , ammonia and honey .
Book illumination
In illumination , the Assis was used as the basis for gilding , since otherwise the gold leaf would not have adhered to the surface. During the late Middle Ages, a distinction was made between “moist primer” ( assis madidus or aurum madidum ) for priming matt gold and “dry primer” ( assis siccus or fundamentum siccum ) for gilding with bright gold.
To achieve the bright gold, the plaster base had to be coated with a poliment , a kind of fatty earth. This was then coated with egg white . After drying, the gold leaf was shot onto it and polished with a tooth or the like. In the case of wet gold plating, the water content in the Assis could be higher and the gold leaf was shot onto the still wet primer. Oily binders could also be used for wet gold plating.
Wood carving
In the case of large church altars in particular , the wooden core of the sculpture was covered with several thin layers of a chalk base. Between the wooden core and the Assis, a canvas cover was glued in several aisles, above all to protect against inevitable cracks and cracks that would otherwise have continued into the paint cover. At the same time, a smooth, even base was achieved and excessively sharp edges and corners were avoided. After drying, the assis was ground with pipe-like sharp stalks ( horsetail ). The last details were worked into this chalk ground before the entire work was polychromed , i.e. painted throughout.
In later times, restorers' ignorance of historical handicraft techniques ensured that both the paint and the chalk ground were removed.
literature
- Hans Huth: Artist and workshop of the late Gothic . Darmstadt 1967, p. 60-62 .
- Hans-Gert Bachmann, Günter Bachmann: Surface gold plating: old and new techniques . In: Chemistry in Our Time . tape 23 , no. 2 , 1989, pp. 46-49 .
- Anna Bartl, Christoph Krekel, Manfred Lautenschlager, Doris Oltrogge: The “Liber illuministarum” from Tegernsee Monastery . Franz Steiner Verlag, Munich 2005 ( excerpt online ).
- Anna Bartl, Manfred Lautenschlager: "How should one make a good goltz foundation". Instructions for shiny gilding in book illumination . In: Restauro . tape 106 , no. 3 , 2000, pp. 180-187 .
Individual evidence
- ↑ Anna Bartl: The "Liber illuministarum" from Tegernsee Monastery . 2005. pp. 506-509.
- ↑ Katharina Möhring: The pulpit altar of the church in Selbelang. Berlin 2000, p. 66. ( Online ( Memento from October 6, 2007 in the Internet Archive ); PDF)