Abstract: The invention provides a photographic printing process which consists of impregnating a support with a photosensitive composition comprising a leuco ester of a vat dyestuff, an acid-generating substance and a catalyst, squeezing out the said support, and exposing the latter to light. The invention also provides equipment for carrying out the process continuously comprising an impregnation tank, a cylindrical irradiation drum equipped with a light source of elongated shape, a neutralization tank, a buffering tank and a rinsing tank. The said drum is equipped to receive, on its outer surface, a photographic plate and a strip of impregnated woven fabric. This process makes it possible to produce monochrome or polychrome patterns with permanent colors.