Lithophany
The lithophany (from the Greek λίθος lithos "stone" and φαίνειν phainein "make visible, shine, appear"; occasionally also light screen image ) is a relief representation in translucent material (often porcelain , plastic or glass ), which only has its effect unfolded in backlight .
A lithophane consists of a thin layer of material, usually a plate, which is illuminated from behind by a light source . The different thickness of the material, which allows the light to shine through to different degrees, creates a special light or image effect for the viewer. Because the stepless light and dark shades are more decisive for the design of the relief than the contours of the image, for example , the lithophane only takes effect when the light source is inserted, which also creates a certain surprise effect.
technology
Originally, this technique was developed in porcelain production, whereby a relief was pressed into a porcelain plate with the help of a model before the firing process . For this purpose, the outlines of a painting or a photograph were freely drawn on thin paper. This paper was placed on a smooth wax plate and the drawing traced. In the next step, the wax plate was held in front of a light source and worked with the model knife, so the light areas of the painting were deepened and the dark areas were left elevated. The wax model is reworked until the painting is completely recognizable through the light falling through it. This work can take several weeks. The finished wax model is placed on a glass plate and liquid plaster is poured over it. When the plaster of paris has dried and hardened, it is lifted from the wax model and forms the mold for the lithophane. Soft porcelain mass is poured into this mold and smoothed. As soon as the plaster of paris form, which attracts the moisture from the porcelain mass, has completely dried, the porcelain layer is lifted off, further dried and finally fired. With the start of machine glass production, lithophanes made of white glass were also embedded in the bottom of beer glasses, which only became visible when the glass was emptied. As a variant of the diaphany , lithophanes intended to be used as window decorations were also made from relief paper in the 19th century.
history
Lithophanes were particularly popular in the mid- 19th century ; the first patent was issued in Paris in 1827 . Shortly thereafter, most porcelain took over factories producing lithophanes, whereby individual products have been copied by the competition. The admissibility of lithophanes was controversial under copyright law. As a rule, lithophane plates were hung in front of window panes , or joined together to form a lamp , which was previously illuminated from the inside with kerosene as a kerosene lamp or with a candle .
Manufactories
The production of "light screen pictures" by the Königliche Porzellan-Manufaktur Berlin between 1830 and 1862 was particularly successful . A Magdeburg manufacturer was the manufacture founded by Carl Heyroth in 1839. In 1849, at the suggestion of Gottfried Henklein , the Plaue porcelain manufacture first developed lithophanes. To this day, they are still being produced and continued with new designs. There are now over 2500 lithophane models in the manufactory.
present
Later the technique was also used for glass production and nowadays with the help of CNC machines for plastics. Thanks to modern LED lighting technology or luminescent foils , lithophanes can now also be produced as very thin, backlit images. The production of lithophanes with the help of 3D printers is comparatively easy . For this purpose, the relief data are obtained from the brightness information of image files with the help of appropriate software and then printed. The plastics commonly used in 3D printing, such as polylactides , are sufficiently light-permeable with layers in the millimeter range.
Individual evidence
- ↑ a b Judgment of the Imperial Court of November 24, 1886, RGZ 18, 102.
- ↑ Rather, Kirsten Dorothée: Die Lithophanien der KPM [Königliche Porzellan-Manufaktur] Berlin (1828-1865). A contribution to the history of porcelain in the 19th century. Dissertation University of Hamburg, Hamburg 1993. Hans Leichter: Berliner Lithophanien. An almost forgotten graphic technique of the Biedermeier , in: Yearbook "The Bear of Berlin", ed. v. Association for the History of Berlin , 23rd year, Berlin 1974.
- ^ Magdeburg lithophanes
- ↑ Ekkehardt Kraemer (ed.): Saxon-Thuringian manufactory porcelain. Glass ceramic. Publicly owned foreign trade company of the German Democratic Republic, Berlin 1985. 3rd expanded edition 1987 pages 19–23 about lithophanes from the Plaue porcelain manufacture .
