“Photo-etching” Technique in Metal Decoration (Focusing on Aluminum Surface)
Indera Irawan B. Mohd Rawi Chandran

Abstract
Photo-etching is a metal plate, usually copper, is coated with a light sensitive emulsion. This is then put into contact with photographic negative and exposed to light, which harden the clean parts of design. When processed the hardened parts of the coating act as an acid resist and the plate is then etched often with the addition of aquatint to create tonal contrasts. However, in this study, the researcher uses aluminum in place of copper as it is easily accessible and costs savy The researcher carries out twenty seven samplings to arrive to a hypothesis that photo-etching technique is an application in making decoration on the aluminum surface. Time is set from two minutes to about ten minutes using seven types of chemicals such as nitric acid, ferric chloride, hydrochloric acid, copper salt, sodium suphite, zinc chloride and sulfuric acid as corrosive agent at different trials or experiment. The findings depict that ferric chloride and hydrochloric acid are found to be the most appropriate corrosive agents to obtain the texture. Beside that, this study also explores the effects of corrosive agents on the aluminum and it is evident that chemicals like zinc chloride and sulfuric acid though a cleaner solution, is corrosive enough to destroy the photo-resist, which sticks on aluminum surface. Last but not least, this research will highlight the uniqueness of photo-etching and extend adequate knowledge on the craftwork. As this technique is rarely used and possessed high artistic value, it has potential to achieve recognition and popularity if given the opportunity.

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