Plastic trays of different thickness and made of different materials are used as food carrying trays. The size and geometry of these trays can also vary depending on the product geometry and the number of products. These trays are shaped from flat plates by using lower and upper moulds by thermoforming method in the state of the art. A method has been developed to reduce the usage amount of plastic trays by 65% by applying pre-treatment on flat sheets or rolls with this invention and different product alternatives were produced with this method.