The Chinese word yinni 印泥 can be translated into English as seal ink, ink paste, or seal paste. The first half of the word “yin” means “seal” and the second half “ni” is translated in my dictionary as “mud” or “clay” so occasionally the Chinese will translate it as seal mud, though this doesn’t sound very auspicious. I suspect someone looked the Chinese word up in an English dictionary in an attempt to be accurate and found this as a possible translation without asking a native speaker of English how it would come across.