Motivation

In the field of restoration and museum exhibition, the production of replicas in the form of physical casts and other similar variants has been established for many years. For this purpose, the originals are exposed to the direct influences of the corresponding materials used for the cast. However, this is undesirable for a large number of unique objects, since damage can also occur with this method. This means that for a large number of historical objects, no replicas can be produced using conventional methods due to their age and fragility. Using a non-contact measuring method, such as the fringe projection method, objects can be captured digitally in an indirect way, with high quality and resolution. Based on this digital data and the new methods of 3D printing, replicas of the desired object can be created relatively quickly and easily. For example, the Gerolsteiner company and the information center in Flonheim contacted i3mainz to have copies of some important historical objects made. For example, on the occasion of the company’s 125th anniversary, Gerolsteiner put on a special exhibition on the history of Gerolsteiner mineral water. Among the exhibits in the exhibition were two boxwood stamps from the founding year of 1888, which were used to stamp the company logo on clay bottles before they were burned. Since the stamps are now owned by a private individual, Gerolsteiner wanted to make copies of the stamps that were true to the original. For an exhibition in the information center in Flonheim, copies of historical weapon fragments made of wood, which are in the fund of the RGZM (Römisch-Germanisches Zentralmuseum Mainz), were borrowed. Since these weapon fragments are not otherwise available, the exhibition period was used to create digital copies of the fragments.

Activities

The objects were measured using the ATOS III strip light scanner from GOM. Measurements were taken with a 3D resolution of 0.07 mm (corresponds to a measuring volume of 150 mm). With the weapon fragments in the Infothek Flonheim, the focus during the scanning process was more on the wooden areas of the objects and less on the golden applications. This is mainly due to the fact that shiny surfaces, such as gold materials, are more difficult to scan due to the stronger reflection of the light. In addition, due to the subtleties of the applications, the customer wanted to make and attach them himself. The fine structures of the objects of both orders required post-processing after the recording and the polygonization process (a meshed 3D model is created from the point cloud) in order to make these structures even more visible. The result of both orders were so-called waterproof 3D copies of the scanned objects, on the basis of which real 3D copies were made with the help of a 3D printer. In the case of the Gerolsteiner stamps, the surfaces of the printed models were manually colored in the restoration workshops of the RGZM and can now hardly be distinguished from the originals.