The Swiss chocolatier Favargar has been in existence since 1826; they should know a thing or two about chocolate. This bar is simply bitter dark chocolate, without any extra flavourings, at 70% cacao content, so it should be a good indicator of the quality of their chocolate. The ingredient listing is fairly good, cocoa mass, sugar, cocoa butter, low-fat cocoa, soya lecithin and vanillin.
How does it taste? Not bad, though a little chalky, and it doesn't snap well. I think the name of it, Plain, is a good indicator of its quality. I don't think I would buy this bar again.