Types of Printing on stamps

Types of printing on stamps - There are various methods of stamp printing and also forms a great factor in determining the cost of the stamp. i.e. Lithography & Line engraving are generally costlier than the other forms of printing. Following are the main methods of printing stamps which every stamp collector should know.

Line Engraving - In this process, the design image is first moulded on a metal (i.e. steel or copper) as of the same size of the stamp and in reverse, which is called MASTER DIE. Then the image from this master die is transferred to the comparatively soft steel surface of a cylinder or roller under pressure. Then from this roller surface, the design image is transferred to form a sheet of may be 100 or 200 stamps as required on a thin steel plate which will be used to print the stamps. These plates can be used in a FLATBED press or curved around a cylinder to be printed in a ROTARY press. The stamp image at this moment is reverse as the stamp can be printed the right way. Finally now, the ink is applied to the metal sheet & then after wiping the metal, the paper is pressed against it. This is also called RECESS PRINTING. There is also an alternative method of obtaining multiple images on a plate formed by duplicate moulds of the original die, which is called ELECTROTYPING.

Lithography - This process works because of mutual repulsion of oil and water. Positive part of  an image is water-repelling substance (hydrophobic), while the negative part would be water -retaining (hydrophilic). In this process, the design is first made with lubricious ink on the plate. Then the acid solution is poured on it, which sticks to all parts of the plate except the design. Then a solution of lubricious ink and water is applied to it, which sticks to design part of the plate. Then printing is done by pressing the paper against the plate.

Photogravure - In this method, the design is first photo printed on a special kind of paper with colored gelatine on it. Then acid solution is poured on it, and then it is transferred to the plate.

Typography - This is also called surface printing or letterpress. In this method, the line s or the designs are raised on the plate.

 

 
 

 

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