Abstract: The invention concerns a heat, steam or water developing diazotype material, containing a photosensitive diazonium salt stabilized with a non-diffusing acid and also one or several developing coats--which could contain the coupling agent--located on the front or back side of the used base material, products avoiding the interpenetration of the active agents, preventing the washing of one coat through the another during coating process, slowing down the absorption of ambient humidity at normal temperature, absorbing the volatile alkaline products at normal temperature, separating the essential reagents to avoid their spontaneous reaction, releasing an accelerating plasticizer during the development, reducing the activation temperature, improving the development by formation of an insoluble salt with the stabilizing acid, releasing a non-volatile weak acid in case of an attack by moisture.