In most cases, 8 to 14 mm thick tempered or triplex glass, characterized by an interlayer between the layers, is used to manufacture door leaves. The most common method used for manufacturing glass panels is the float method. Through this technology, the glass is characterized by a perfectly flat surface and the absence of optical defects. I have worked in a door manufacturing firm, so I can do this by hand. But generally, it is best to order prefinished doors because this is the best solution.