Printing method

A method for preparing a printing screen, having a latent image thereon, for use in a screen printing process wherein, after printing a first image, the screen may be re-imaged to permit printing of a second, different image, sadi method comprising:

• (a) providing a clean hydrophilic mesh surface consisting essentially of an intrinsically substantially hydrophilic material;
• (b) applying, in direct contact with said surface, a substantially thin, non-occlusive, hydrophobic and oleophilic layer of material, said layer, when applied, conforming to said mesh surface so as to avoid blocking openings comprising said mesh surface, said material of said layer having an affinity for said mesh surface and being capable of being removed and re-applied without substantial change to said mesh surface or substantial interruption of the printing process;
• and
• (c) forming said latent image on said surface by removing, in an image-related configuration, a portion of said layer from said surface.

A method for forming a latent image on a printing screen in an automatic manner, comprising:

• (a) providing a clean screen having a mesh surface which is intrinsically substantially hydrophilic;
• (b) automatically moving said screen through a plurality of stations, said stations collectively performing the following process steps on said screen;
• (c) applying a layer of material to said screen which provides a non-occlusive hydrophobic and oleophilic surface which avoids blocking said mesh surface;
• and
• (d) forming said latent image on said screen by removing selected areas of said hydrophobic surface in an image-related configuration by selective application of energy to said hydrophobic surface.

A method for automatically forming and changing a latent image on a printing screen which relies on the immiscibility of hydrophobic and hydrophilic materials to print images therefrom, said method comprising:

• (a) providing a screen having an uncontaminated mesh surface which is intrinsically substantially hydrophilic;
• (b) applying a material to said surface which provides a non-occlusive hydrophobic and oleophilic surface where applied;
• (c) forming said latent image on said screen by removing selected portions of said non-occlusive hydrophobic surface in an image-related configuration by the selective application of energy to said hydrophobic screen surface;
• (d) removing all materials from said screen surface, including all remaining portions of said hydrophobic surface, thereby exposing said hydrophilic screen surface;
• and
• (e) automatically moving said screen surface through a plurality of stations which collectively perform steps b-d while controlling the operation of steps b-d, using steps b and c in sequence to place a latent image on said screen and by using steps d, b and c, in that sequence, to change said latent image on said screen.