Abstract: Flat bed thermal printing apparatus adapted to print information on to an elongate substrate, or on to products disposed upon the substrate, at a printing area within the apparatus, the said substrate being movable through the apparatus in a step by step movement, with a stop for printing between each step, along a path which causes the substrate to be disposed in a substantially flat position as the substrate is stopped at the printing area after each step wherein the apparatus comprises a printing head provided with a multiplicity of individually energizable dot type thermal elements, means to move the printing head relative to the substrate while the substrate is stationary at the printing area between its stepwise movements through the apparatus with the substrate in its substantially flat disposition, means selectively to energize the said printing elements during movement of the printing head to effect printing and means positively to hold the substrate in position at the printing area during printing.