Etching process is described as an incised carving process, involving application and rubbing of the extra ink into contours and fissures created on metallic surface, usually copper and zinc, by the controlled corrosive action of acids, besides other acidic solutions.

Once the ink percolates and fills all the cracks and crevices, the excess is removsed by polishing relief surface by applying suitable metal polish.

To make the action of acids in the etching process well within control, various negative catalysts or resists are initiated.

The physical and chemical properties of each of the resist vary, and so is the time of action-reaction process.

Moreover, the variations in the depth of crevices, besides their thickness and lightness are managed and controlled by calculating the total immersion time of the metal in the acid.

More the immersion time of the metal in the acid, more is the depth of bite and therefore darkness. If a light texture together with less thickness is required at a particular point on surface, then, a suitable resist is applied by taking out it out of acidic bath to hinder the acidic action of the corrosive material at that point of surface. The metal plate is again immersed into the acid solution to continue with the etching process.

Etching Process: Different Types There are three types of etching processes, each varying in style, method, besides physical and chemical functioning. These include:

• Wet Etchings
• Dry Etching
• Wet Etching:
• In this simple, cost effective and easy etching process. The solution is put in the container along with the massed material that enables careful etching.