Photo etching, sometimes known as chemical milling is a process of making metal materials by removing unwanted pieces from flat sheets through acid erosion. In the old days, a material resistant to the acid corrosion, such as wax, was used to coat the metal, and then the needed image was inscribed through the wax using a sharp item. The acid was then spread on the surface to cut deep on the metal, thus producing the required image. The metal sheet was then cleaned, and the coat removed.

The modern-day photo etching still makes use of the same principle. A light-sensitive and photoresist material is used to coat a chemically prepared and greased metal on both of its sides. Then the resist is fixed by exposure of the metal to ultraviolet light. The areas of the metal that are not exposed to the light are then removed in a chemical developer, leaving the areas of uncoated metal. The sheet is then moved through a hot acid bath. The coated areas are not affected by the acid, whereas the uncoated regions are etched. The process is repeated until the right depth of etching is achieved.

A device known as a photo-tool is used to prevent the exposure of the resist. The photo-tool is a device such as a sheet of transparent film with a black circle inscribed on it. When the resist coated metal sheet is fixed with the photo tool on it, then exposed to ultraviolet light and lastly developed. The metal will have a circle of the exposed metal in between a coated area of the resist. The metal can have then been etched to the required depth.

However the metal is coated on both sides. An image can be developed and printed on both sides of the metal. If the material was etched halfway through from the back and the front, any area where the two images coincide will produce a hole right through.

Photo etching services provides a flexible, inexpensive, and fast way to make a wide variety of photo-etch parts. Chemical etching can produce many types of metal, including unique materials like soft magnetic alloys, metal-clad ceramics, molybdenum, among others. Applications for chemically matched components range from decorative, mechanical, aerospace, giftware, etched pin badges, scale models of railroads, jewelry, etc.

Chemical milling is also an ideal medium for making distinctive giftware for organizations, events, commemorations, and brands. Power to produce an exceptional photo in a substantive and durable metal form photo-etched gifts that stand out from the common types of promotional products.

After photo etching services are done, with a highly sensitive process where there are some small pieces, they are then washed off the resist film and dried. The final product is then ready to be collected by the requester. In another way, when etching is done, with signs, they are watched of the resist film and dried in the same way as the first method but then filled in the different colors as requested by the customer, then they are ready to be given out to the requester.