This notebook presents information on a limited number of important early synthetic dyes as recommended by the extensive work of Dr. Helmut Schweppe in the field of dye analysis. A great deal of the data has been abstracted from the well-known encyclopedia on dye structure and properties, the Colour Index, published jointly by the American Association of Textile Chemists and Colorists and the Society of Dyers and Colourists. The purpose of this manual is as an aid to textile conservators in their laboratories. It is distributed by the Conservation Analytical Laboratory, Smithsonian Institution, with the kind permission of the American Association of Textile Chemists and Colorists. For a complete review of all known dye structures and chemical properties of dyes, the reader is referred to the master volumes of the Colour Index.