OK, Here's a crash course in photo etching. I do this for a living so I have all the equipment. If you want to try this on your own it is the same process used to make printed circuit boards. The ecthing plates I make are used for engraved stationery; letterhead, envelops, business cards and wedding invitations. One source for metal, resist and acids that I have used is
http://www.graphicchemical.com. You may also want to do a search for printmaking supplies or check out the bookstore at your local college. If your local college offers printintmaking in the art department they might even make the plate for you.
Here's how I made the plate for this box:
Step 1: Scan the photographs and manipulate them with ever software you have. I used Photoshop and Illustrator.
Step 2: Generate your film. This can made with a copy camera, an image setter, a transparency. you can even use a Sharpie and a piece of clear acetate.
A couple of points here:
The image on the film needs to be the correct size. The film will placed directly on the plate to burn the image so make sure the size is correct on the film.
Photo sensitive resists for etching metal are referred to as either NEGATIVE working or POSITIVE working. Read this carefully it gets a little confusing. If the resist you are using is a NEGATIVE working resist you need a positive image on you film to expose it. As you look at your film the areas that you want to etch should be black and the areas you
do not want to etch should be clear. This type of film is referred to as a Positive. If you are using a Positive working resist the opposite is the norm. The areas you want to etch should be clear on the film and the areas you do not want to etch should be black. This type of film is referred to as a Negative.
Step 3: Burn the image on the plate. This is done by placing you film on the plate coated with photo resist and exposing it with a light source. Different resists require different light sources. Refer to your instructions for exposure time. After burning the image develop it. The areas you want to etch develop away.
Step 4: Etch the plate. Place the plate in a tray of acid. For copper I use ferric chloride. For steel or zinc you want a nitric acid. The acid should cove the plate by about 1/4" deep. Gently rock the tray every few minutes to agitate the acid. After the image is etched to the desired depth remove and clean the plate. This is a slow process, be prepared to spend at least an hour for etching copper. You want a depth of at least .010" the thickness of 2 pieces of 24 lb. paper
Step 5:Back fill the image with white epoxy resin. I used Colores from Rio Grande
http://www.riogrande.com/
Step 6: Sand the epoxy flush with the surface of the metal with at least 600 grit.
Step 7: Tarnish the copper. This provides contrast so you can see the image. Let it tarnish naturally or use a weak solution it nitric acid.
Step 8: Clear coat the plate to protect it and it is ready to inlay.
If you have any more questions let me know.
Rick Doby
