and method of this invention are suitable for many uses where robustness of an ink jet image is important such as posters banners displays labels and the like the method of this invention is also particularly suitable for use with a wide variety of packaging materials e g a heavy weight paper card or board the materials and method of this invention are also particularly suitable as a security printing system and this aspect of the invention is especially preferred after the material has been sealed by heating it is no longer receptive to inks and is thus difficult to alter and offers high levels of protection from fraud and forgery in an additional aspect of the invention when it is used as a security printing system a suitable mark or pattern such as for example a holographic pattern may be embossed on or transferred to the image at the heating stage this pattern may be carried on the inert sheet used in contact with the image during the heating stage or may be carried on a roller or stamp used in contact with the image at the heating stage various ink receiving materials which comprise a combination of a particulate polymer and a hydrophobic binder are already known for instance u s pat no 3 968 319 discloses a particulate polymer for use in paper coatings u s pat no 4 196 253 discloses a paper coated with a binder and organic.