A method of preparing a printing form precursor for printing, or a printed circuit board precursor or a semiconductor precursor, the method comprising the step of applying electromagnetic radiation having a pulse duration of not greater than 1×10−6 seconds, in an imagewise manner, to an imagable surface of the precursor. The imaging process may cause ablation of the coating of the precursor or permit its development in a developer. In each case the imaging radiation needs not be tuned to imaging chemistry (if any) present in the coating. Alternatively the imaging process may induce a change of hydrophilicity or hydrophobicity, or other change of state, of an uncoated substrate.