As Galerieton refers to the darkening of old photographs, graphics and especially oil painting .
There are several causes for the dark brown to almost black discoloration, which becomes increasingly stronger over time. The gradually progressing oxidation of the oil paint and binding agent as well as the yellowing of the varnish give rise to the brownish hue observed; the omnipresent dust, on the other hand, makes the picture appear darker and darker through gray and black tones. The gallery clay is created all the faster, the darker the finished painting has been stored to dry.
Painters and restorers sometimes made their pictures look older from the start with colored varnishes. The best-known examples of paintings changed in their effect by the tone of the gallery are the self-portrait of Jacopo Tintoretto and the depiction of a Dutch rifle guild by Rembrandt, later called Night Watch .
In the 19th century, paintings were also deliberately created in the gallery clay as a trick in order to create a reference to the painting tradition of the Dutch of the 17th century. This trick was understood by contemporaries as a kind of quotation . An example of this is the painting The Cardsharps by Ludwig Knaus, created in 1851 .
- cf. Notes on the yellowing of oil paints. Website of the company Kremer Pigments ( Memento from December 5, 2008 in the Internet Archive ).
- Ute Ricke-Immel: The Düsseldorf genre painting . In: Wend von Kalnein : The Düsseldorf School of Painting . Verlag Philipp von Zabern, Mainz 1979, ISBN 3-8053-0409-9 , p. 159