Transylvanian glass icons ae very specific heritage items of Romanian folk art, produced from middle of 18th century until now. The present reserch reports the results of a study on the organic components of the paint layers, analyzing the binding media of a series of glass icons belonging to three important icon making centers: Nicula, Old Country (Tara Oltului) and Brasov area (Şcheii Braşovului). The analysis of the binding media has been done by means of gas chromatography coupled with mass spectrometry (GC/MS). The applied analytical procedure allowed the characterization of the proteinaceous, polysaccharide and lipid-applied analytical procedure allowed the characterization of the proteinaceous, polysaccharide and lipid-resinous content of binding media starting from a unique microsample. Results showed that a wide range of materials were used by the icons painters, mostly applied as mixtures of a proteinaceous material and a lipid one. The proteinaceus component proved to be mainly egg, though animal glue and casein were ascertained too, and proteins were often mixed;the lipid material was identified as linseed oil. In some of the icons pine resin and saccharide material were found. Data also highlighted that though the materials used in all the glass icons under study are similar, some particularities could be observed in the painting technique of the studied producting centers and icon painters.