"cirè-perdué, from french language;   cirè is french for wax,  perdué means lost  hence "wax lost " or lost wax. This refers to the part of the process where the wax pattern is burnt or melted from inside the ceramic shell coating. The term sincere is a term that has it's roots in foundry history, any faults or holes in a casting were often mended by filling the blemish with wax tinted to a similar colour, hence the term sincere meaning without "wax".