A method and a carrier medium carrying code to execute a method of
designing a carton. The method includes accepting carton structural
information, forming a 2D unfolded model of the substrate that when cut
and folded forms the carton, and forming a 3D model of the carton. The
method further includes displaying a 2D view of the unfolded carton
design, and a perspective view of the 3D model. A user has the ability to
manipulate the view of the 3D model, and also to select a flap of the
carton on perspective view. As a result of the selecting, the method
modifies the 2D unfolded view to be of the selected flap shown in an
orientation suitable for designing the selected flap. The user designs
the flap and the method accepts the design. The method includes modifying
the perspective view of the 3D model to include any changes made in the
design.