1. Basic Principle

• Offset lithography has been used to decorate pottery for many years - it works on the principle that oil and water do not mix. It uses a flat printing plate where the image area attracts ink and the non-image areas attract water (repelling ink).

2. Process Steps

• Design Creation: A detailed design is prepared, often digitally.

• Plate Preparation: The design is transferred onto a lithographic plate, usually made of metal.

• Inking and Printing:

• Ink is applied to the plate.

• A rubber blanket (offset cylinder) picks up the inked image from the plate.

• The image is then transferred (offset) onto a paper or decal.

3. Transfer to Pottery

• The printed paper or ceramic decal is applied to the pottery item by hand or machine.

• The piece is then fired in a kiln, causing the design to fuse permanently with the glaze layer

4. Advantages

• High-quality, detailed prints

• Suitable for mass production

• Consistent results with complex designs

5. Applications

• Decorative tableware

• Commemorative ceramics

• Branded pottery items
  

Multi-Color Process:

• Separate Plates for Each Color:
  Each color in the design requires its own lithographic plate. So, if the pattern has red, blue, and yellow, then three plates are needed. 

• Sequential Printing:
  The colored inks are applied one after the other, with precise alignment (called registration) to ensure the pattern lines up perfectly.

• Layering on Decals:
  The multicolored image is typically printed onto a single decal paper, which is then transferred to the pottery in one go.

Firing:

• After application of the transfers, the ware is glazed and then fired in a kiln, making the design permanent and vibrant.