Plate Making

Steel Cliché Plates

For applications that require precision printing and high volume, steel cliché plates are used.
A steel cliché plate is manufactured in the following way:

The surface of the steel cliché plate is initially coated with a light-sensitive material. Before exposing the plate to light, a film containing the desired image is placed face down on it.

The film and plate are then exposed to light. The light hardens the area of the plate not covered by the film.

The areas that were covered by the film remain soft. The soft area of the plate is then removed by soaking it in a developer bath.

The area containing the image leaves an impression that will be etched in a bath consisting of nitric acid, chlorine (III), iron, or similar chemicals.

The actual etch depths for a steel plate varies depending on its intended use. In general, the etch depths are 16 microns for fine scripts, and 22 microns for standard scripts.

Screened Images

A second method for etching a steel cliché involves screening the image onto the plate. This method is usually used for large images. A screen (or dots) is used because it eliminates the problem of having the doctor blade sag into the etched image, which causes 'scooping' of the ink.

Alcohol Wash Plates

For small production runs, polymer plates can be used. These plates, if handled properly, will have a production life of several thousand prints. They are metal-based plates and are coated with a light-sensitive material that becomes hard when exposed. When a film is placed on the plate and exposed, the image zones that were covered by the film remain soft. The plate is again exposed, but this time with a screen-dotted film. The "dots" on the plate remain hard, and, after washing the plate with the appropriate developing agent, small flat cones remain. The screen-dotted process for plate development must always be used when working with polymer plates.

Water Wash Plates

Another more recent development in pad printing cliché plate technology is the use of water wash polymer plates. Instead of a chemical, lukewarm water is used as a developer. The exposure process for these plates is the same as for alcohol wash. By air-drying the plates, and then exposing them to UV light, the polymer plate's production life is increased significantly.

Film Quality

The quality of the finished etched image is dependant on the type of film used during plate exposure. Teca-Print only uses high-quality film materials for exposing cliche plates.