Advantages and limits of chemical microanalysis especially for characterization of binding media are discussed and demonstrated by the technological examination of a Fayum portrait in the papyrus collection of the Osterrichisches Nationalbibliothek Wien. Several paint samples were analyzed by means of microchemical methods to determine the character of the paint layer. The range of pigments identified is summarized as follows: calcium sulfate, white lead, white earth, red ochre, green earth, and charcoal. The identification of the components of the binding medium was limited by the analytical procedure. However, the composition has been identified as a mixture of egg yolk or casein (exact identification was not possible) as main component and wax as minor component. In other cases the problem under investigation-e. g. , the aging phenomena of the materials-requires the use of modern analytical equipment: sometimes development work is necessary for its suitable application. Selection and preparation of samples is critical.The sampling method described allows the preparation of single grains from pigments from colored etchings and subsequent semiquantitative analysis of definite particles by means of scanning electron microscopy and energy-dispersive x-ray analysis. The sampling methods were shown to be suitable for the analysis of particles smaller than 2.5 micrometers. Examples of the application of the method and analytical data are given. See also AATA 20-631 for related study.