The ceramic material called kera vitral was developed at the Ceramic Manufactory in Znojmo, former Czechoslovakia in 1967. Its special properties were caused by the composition of the ceramic material. The high content of kaolin and the whitish color brought it closer to porcelain in appearance, but the special admixture of quartz and resins ensured its above-average hardness and strength.
Kera vitral is a relatively heavy material, but this was considered more of an advantage and proof of durability. It was said to be "almost unbreakable" - resistant to beating, cracking and common detergents. It can also handle a dishwasher, and because it is a high-heat ceramic, it is also suitable for baking in the oven.
It is therefore ideal for use in restaurants and hotels. And in hotels, kera vitral services have really been used. They were also used, for example, in a tower hotel in Ještěd mountain. The dining set for Ještěd was designed by the artist Karel Wünsch (1932), who remembered its creation as follows:
"At that time there were technical ceramic factory in Teplice, where they made insulators for high lines and also produced cups and similar things as an associated production. And there they developed a new mass, they called it a stained glass, and it was something between porcelain and ceramics. It was very hard, it was a highly fired pottery for the insulators and, unlike porcelain, it could be glazed, so I opted for the kera vitral, letting it be glazed to brown, and to make things all right, I also went to the ceramic factory first. I had about three sets made and first we tested it at home, my wife said it was hard, it was badly handy, then Mr. Pikal had just arrived, and when he saw it, he got excited about it. He had a strong word in his industry and to those directors and deputies he said: That's it, that's exactly it! And that was it. "
If Karel Wünsch mentions Teplice as the place of origin, he is not necessarily wrong, because the Znojmo ceramic factories really had a branch there; Other sources state that Znojmo and Teplice are the place of production (and invention) of the kerital vitral (the designers were demonstrably connected to the vitral connection in Znojmo).
And how was kera vitral evaluated aesthetically in the late 1960s? The Czechoslovak Glass Review stated that the products, with their more robust appearance, fit perfectly into the rustic fashion of the time. In a promotional article, it even announced "the return of ceramics to the contemporary interior and urban homes", but for sure it did not forget to add that kera vitral is just as well suited for weekend cottages.
The first cups were cups with saucers and mugs with vertical stripes, under the name Viktoria. Their designer was a certain J. Daniel. However, as early as the end of the 1960s, the first larger tea, coffee and dining ensemble Astra was also formed, again attributed to J. Daniel.
The first series had a honey brown and olive green glaze, later a dark brown and blue hue was added. For all, a simple relief decor was applied, which could stand out in combination with a semi-permeable "glass" glaze, which fades (thinens) in the raised surfaces, while in the deeper parts of the decor it acts in its darkest (richest) shade. Already in the early 1970s, decors combining the aforementioned dark glazes with transparent glazing and decorative printing also appeared.
Source: brusel58.blogspot.com, Citations and literature: Milena Lánská (red.), Vzpomínky na Ještěd, Liberec 2015, s. 19., Časopis Czechoslovak Glass Review, roč. 1968: s. 385, roč. 1970: s. 46-51, 1972: s. 82-85., Pictures: own archive, Instagram, Pinterest