Abstract: The invention relates to a process for the preparation of a photosensitive photoresist solution, characterized in that a novolak resin and a diazonaphthoquinonesulphonyl chloride are dissolved in a solvent from the group consisting of the photoresist solvents, a proportion of from 1 to 70 mol % of the phenolic hydroxyl groups of the novolak resin is reacted with diazonaphthoquinonesulphonyl chloride in the presence of a base, and the reaction mixture is washed with water and optionally diluted with further photoresist solvent.