Sheet of packaging material for producing a container and method for producing containers

A sheet of packaging material suitable for being folded, filled with a product and sealed so as to form a package (10), comprises a receiving region (7) intended to receive an opening device (12) of said package (10) attached thereon, said sheet of packaging material further comprises two reference marks (14) detectable by a detecting unit (23) of an applying device (24) arranged for applying said opening device (10) on said receiving region (7); a method for producing a package (10) comprises the steps of folding, filling and sealing a sheet of packaging material (1) to obtain said package (10), said sheet of packaging material (1) comprising a receiving region (7) intended to receive an opening device (12) of said package (10) attached thereon, said sheet of packaging material (10) further comprising two reference marks (14), the method further comprises the step of detecting said reference marks (14) and selecting a subsequent action to be performed on said package (10) and/or said opening device (12) on the basis of the detected position of said reference marks (14).