Professional and ethical questions and dilemmas, the search for know-how and for appropriate methods and techniques also outside of working hours have led the experts in the field of conservation and restoration of cultural heritage to establish the Slovenian Society for Conservation-Restoration, which served as a platform for sharing ideas, the know-how and good practices among conservationrestoration experts. Today, the society's mission remains the same. The studying as well as ethical and conservation-restoration approaches to preserving cultural heritage are almost as old as the cultural heritage itself. However, there are different kinds of cultural heritage gradually joining the whole, since with the passage of history new materials are born that are technologically different from the basic materials such as wood, stone, metal, glass, etc. The ethical attitude, however, stays and must be the same towards the entire heritage that cannot choose the material it is made from. When I was asked to deliver this opening address, the question as to how Slovenian experts have covered the problem of conserving and restoring works of art made of plastic materials immediately presented itself. The society has 300 members and I am sure that some of them have already tackled the question of conserving and restoring plastic objects, be it as a stand-alone artefact or as a part of another useful object. And yet, no comparable institution in Slovenia has an independent department for restoration of plastic materials. This shows that despite a very long and very intensive presence of the material in our lives, this branch of restoration profession has been neglected, and will need much attention in the future in order to fill the resulting gap.

Also important is the problem of handling plastics as a stand-alone work of art on one side, and as restoration material for conservation-restoration procedures on different works of art on the other side. This perhaps raises the question of compatibility, reversibility and, after all, suitability of this material to be used as restoration material. The symposium on this issue is perhaps a great opportunity to give the accompanying ethical questions the highest priority.