cut out section 20 will automatically form a corresponding marker 30 which may appear as a projection extending from the cut out section 20 the marker 30 may also be used for alignment however to provide both reference and alignment two markers 30 and 32 are preferred with the different markers having different shapes as shown in fig9 d in this way no error can be made in alignment particularly if the cut out section 20 is adapted to the die 10 by use of a robot the two dimensional cut out section s 20 of all of the different configurations shown in fig2 9 have mating ends 35 which form one or more seams when the cut out section 20 is placed or wrapped over the die 10 the seams are formed by abutting the mating ends 35 together as shown in fig1 a in many instances an overlap of the mating ends is preferred and the thickness of the seam formed at the overlapping mating ends may be reduced by mechanical or automatic means to minimize the thickness formed by an overlapping seam the mating ends 35 can be beveled as shown in fig1 b or otherwise contoured as for example as shown in fig1 c to form an interlock at the mating ends 35 where the tooth preparation results in a cut out section 20 having a complicated surface configuration and or where many seams will be necessary the mating ends 35 should be beveled to accommodate an overlap moreover by overlapping the mating ends 35 the thickness of the seam can be controlled the.