The research subject of master thesis is is paper work entitled Omizje, property of the Modern Gallery in Ljubljana, by the great Slovenian representative of high modernism painting, Marij Pregelj. The painting's condition is examined and its main problem areas adressed. The technology and materials behind the art work are highly specific as it is painted on a paper medium, with polyester resin as the binder and polyvinyl acetate resin as the finish layer. This together contributed to planning and carrying out conservation-restoration procedures. Painting samples were analysed and used as the basis for technological studies with which the painter's techniques were thoroughly researched. These technological studies also aided in finding the appropriate conservation-restoration materials and techniques, also considering conservation principles for conservation-restoration procedures. Conservation-restoration procedures for paintings on paper are presented.