Although it is worth noting that the windows were rarely done, in ancient Greece, buildings with windows were considered a luxury. Our ancestors of the Slavs came up with shutters. Since the production of glass windows for our ancestors was not just a luxury, but something from the field of science fiction, they used mainly fish, and a bull bubble, and a canvas, thin wooden plates, mica, even ordinary ice. The mica was considered the most suitable material for the windows for a long time, because the quality of the first glass left much to be desired. But nothing is in place and now the glass recipe is available everywhere, its quality is much improved, the window has ceased to be the subject of luxury.