In a printing process that can be used on a raw textile substrate in natural and/or artificial cellulose fibers, alone or in combination with raw and/or dyed yarns of different composition, a printing paste is directly applied on the substrate, through a printing matrix carrying the pattern to be reproduced, the printing paste comprising a highly concentrated oxidative agent in a highly alkaline environment, together with stabilizing agents and complexing agents suitable for making the action of the oxidative agent gradual and for preventing catalytic reactions being triggered that could lead to the fibers being damaged.