This paper outlines the conservation and restoration of a GRP lounger designed by german design icon Luigi Colani in the late 1960s which is held in Die Neue Sammlung, The International Design Museum, Munich. The red orange lounger is made of glass fiber reinforced polyester resin and manufactured by hand lay-up. It is part of a garden furniture collection that Colani designed in 1967 and that was produced in 1969 with only a small number of copies. With its anthropomorphic, flowing and organic shape, it is a typical Colani piece of furniture. The garden lounger was added to the collection of Die Neue Sammlung in 2003. Before, it had been privately owned and presumably been temporarily positioned outdoors – as is usually the case with garden furniture. Thus the piece had been exposed to environmental influences like weathering, fluctuations of temperature/humidity and ultraviolet radiation. In addition, use by the owner led to characteristic signs of wear at exposed positions; also, inappropriate cleaning methods seem to have been applied. Therefore the lounger showed several damage symptoms such as inter-layer delamination in the GRP bond as well as a partial whitish discoloration accompanied by loss of surface gloss of the polyester resin (especially on the seating and back). Further, mould stains affected the visual appearence. In that condition it was impossible to think of exhibiting the lounger in the museum since the optical changes would have heavily attracted the attention of the beholder. A conservation treatment was urgently required. In 2012, the conservation measures were undertaken in the Conservation Department of Die Neue Sammlung in collaboration with the Munich Chair of Conservation, Arts Technology and Conservation Sciences. The treatment aimed not only to stabilize the lounger´s condition from a conservation viewpoint (in terms of cleaning, disinfecting and consolidating delaminations/loosed gelcoat patches), but also to obtain a more uniform and aesthetically pleasing appearance with regard to surface color and gloss. Concerning the latter, the partially stained polyester resin surface could be brought closer to homogeneous aged areas by using an airbrush gun as retouching tool. In this connection, focus was on both applying an unpolar separating layer (which acted also as adhesive) between polar plastic and paint layer and on protecting the glazing sprayed paint via a matte glossy coating. All work was carried out under the sign of a preferably high level on reversibility. As a result of these treatments, the lounger now shows a stable condition as well as an „exhibition ready“ appearance that does not deny history and use of this rare design piece.