Invented by a pastry chef

The French pastry chef Joël Lantelme who was always asked to prepare cakes for variating numbers of portions was fed up buying numerous opera frames and was looking to reduce leftovers.
He had the bright idea of the Multi OPERA.
The concept is so clever! 4 removable rulers in stainless steel, with slots to create equal and regular portions, and adjusting to the desired size.

He presented a protoype to a friend: Jean-Louis Aubert, a caterer, who immediately embraced the invention. 

Both became partners in order to finance the manufacturing and the patent.