One of about 20 known examples of Oceanic ethnographic shields presumably came in 1858 to Vienna; it now belongs to the Ethnographic Museum. The face of it consists of painted matwork with a mosaic of square mother-of-pearl fragments of nautilus shell stuck into a brownish cement. A preliminary scientific analysis showed that about a 12% loss of mosaic was due to the reduction of protein at the backside of the shell pieces. The cement proved to be made from the black pigmented mass of the local parinarium nut. Different glues of low viscosity were tested for fixing and filling losses, with the addition of new mosaics without further retouchings. The materials selected for use were silicone gum (Elastosil A 33), PVA emulsion (Planatol BB superior) and hydroxypropyl cellulose (Klucel Hf 10% with Isopropanol) for mat fixing of loose pigments. -- AATA