Filling the missing areas is one of the most important phases in the restoration process, which directly affects the cultural objects. This process involves many ethical issues, as the choice of materials or the requirement of recognition and reversibility of these interventions. We have carried out a research in the Museo de Prehistoria de Valencia about the application of detachable restorations on different archaeological materials like pottery, bone, glass or mosaic. This research attempts to minimise damages on the original piece and guarantee an easy removal if it is necessary.