Disclosed is a method for designing a virtual mould used for manufacturing a corresponding physical mould adapted to be used in manufacturing of a dental restoration for a patient, wherein the method includes obtaining a 3D representation of the patients set of teeth virtually designing at least a first layer and a second layer of the dental restoration, where the first layer is part of a first portion of the dental restoration, and and virtually designing the mould, where the inside surface of the mould is adapted to match the combination of at first portion and the second layer, where the inside surface of the mould corresponds to the shape of the dental restoration, where virtually designing the mould comprises designing a virtual retention structure of the mould.
