We are excited to have guest artist, teacher and author, Mona Clee, with us in June at Silvera Jewelry School. With her permission, I'm sharing a modified version of her article from ArtJewelry Magazine on etching as a little preview, a taste of all the tips, techniques and variety of approaches she will cover during the workshop.
Want more? check out her upcoming workshop, Saturday and Sunday, June 16 & 17 at Silvera Jewelry School in Berkeley, CA, Etching Workshop: Etching Sterling, Copper, Brass & More. Learn how to etch other metals, more techniques and get one-to-one help and patient support. You can register online anytime.
Easy Etching by Mona Clee
Metal Etching is an exciting process you can use to transfer virtually any image or pattern to copper, nickel or brass.
To transfer an image to metal, you'll need to use a material that will "resist" the dissolving action of acid. Where you apply the resist, the metal will be protected; everywhere else, the acid (ferric chloride) will etch the metal, leaving the protected metal in a raised image.
One of the more versatile resists is a blue acetate film known as Press-n-Peel (PnP) paper. An image or pattern photocopied onto the matte side of this paper will transfer as a mirror image. If the direction of the pattern is important or includes lettering, consider what you'll use the etching for, and adjust the orientation of the image or letters so that they will read correctly on the finished product. You may need to photocopy the pattern onto a transparency and then flip the transparency appropriately before photocopying the image onto the PnP paper.
 Transfer your artwork to PnP paper. Use a photocopier with a carbon-based toner to transfer copyright-free artwork or original designs from plain paper onto the matte side of the PnP paper. (PnP paper comes in 8.5 x11-in. sheets). The copier should be set to give the darkest image possible without smudging clear areas. The photocopied image on the PnP paper will act as a resist on the metal. The inks used in ink-jet printers generally do not work for transferring images with PnP paper.
Pretest your iron.
The optimal heat for transferring images with PnP paper is just below the temperature at which the backing film on the PnP paper begins to buckle. Since irons vary in temperature, it is critical to pretest your iron.
Begin testing by seating your iron one or two settings below maximum. Place a piece of scrap metal on a heat-resistant surface, and place the PnP paper on the metal, matte side down. Iron the paper. When the paper buckles, turn the temperature down slightly. That temperature is the optimal temperature.
Cut and prepare the metal. Use a metal shear or a jewelers saw to cut a piece of metal that is slightly larger than your image or pattern. The metal must be flat. If the metal is not flat, use a rawhide mallet to flatten it on a bench anvil.
Use a scouring pad or sandpaper to clean the surface of the metal. Rinse the metal with water and dry it, taking care to handle the metal by the edges to keep skin oils off the surface. Wipe the metal surface with rubbing alcohol immediately before attaching the PnP paper.
Apply the PnP paper as a resist to the metal. Cut your image or pattern from the PnP paper, leaving a metal border at least 1/4" in. (6.5mm) wide around the image. Place the metal on a heat-resistant surface and place the PnP paper, matte (image) side down on the metal. Use a circular motion with the iron to apply heat evenly across the surface of the PnP paper. The metal plate will become very hot, and the image will become more pronounced through the PnP paper's film backing as the transfer takes place.
Peel the PnP paper from the metal. When the metal has cooled, lift one corner of the PnP paper, observing the transfer closely to make sure the image has completely transferred. If it has not, apply the iron again until you are satisfied with the transfer. If there are still any areas of the design that did not transfer, fill in and touch up the image with black permanent marker or nail polish.
Prepare for etching. Cover the back of the metal sheet with contact paper, coating the edges with nail polish or another resist to protect them from etching.
Use Styrofoam to keep the metal afloat during etching. Cut a piece of scrap Styrofoam about the size of your metal and at least 1 in. (25.5mm) thick. use double-sided tape or duct tape attached sticky-side out to adhere the back of the meal to the Styrofoam.
Put on eye protection, an apron, and nitrile gloves before handling any acids. Make sure there is adequate ventilation in the area where you will be etching. See "Safety Notes," below for more information on handling ferric chloride.
 Etch the metal. Pour just enough ferric chloride into a glass dish or plastic container to allow the meal to float easily. Put the metal plate face down in the acid. Gently rock the container to remove air bubbles fro the surface of the metal. Cover the container and leave the metal for approximately 1.5 hours. A shallow etch for a metal clay texture plate can be achieved in 30 to 45 minutes. See "Etching Tips" below for resist-endurance times.
Clean the metal and remove the PnP resist. Wear nitrile gloves or use plastic tongs to remove the metal from the ferric
chloride. Submerge the metal plate in a solution of 2 cups (473.2mL) water and 1/4 cup (59mL) baking soda to neutralize the ferric chloride. Rinse the piece in clear water and remove the tape. Remove the PnP resist with acetone and a scouring pad. Finish the piece with a brass brush and soapy water. This should remove all traces of the resist and any other stains. It will also polish and burnish the metal, giving it a smooth, attractive finish.
Try these applications for etched plates. The finished etching can be made into a jewelry item, or you can use an etched pattern as a texture plate for metal clay or polymer clay. If you have etched into brass or nickel, you can use the plate to roll-print the texture onto sterling silver.
Wear safety glasses and nitrile gloves to keep the ferric chloride from contacting your skin or eyes. Wear an apron to protect your clothes. Do not touch your eyes if you have been handling ferric chloride. Do not inhale any vapors that may be given off by the ferric chloride. If skin or eye exposure occurs, rinse with water for 15 minutes and seek immediate medical attention. Take empty bottles of ferric chloride to the nearest official hazardous waste disposal site.
To reduce your contact with the acid, etch small test panels using a timer so you know how long to leave the metal in the acid to achieve the desired depth of etching.
Ferric chloride will stain everything it touches. Cover your work area with several layers of newspaper to protect the surface. if you rinse the ferric chloride into a sink, scrub the sink afterward with abrasive powder to remove any stains and residue.
A variety of materials can be used as resists - even a black permanent marker can be used to draw original artwork directly on the metal. Press-on letters, rubber stamps using permanent ink, and stickers from craft-supply stores will all work as resists. More traditional resists include lacquer, shellac, nail polish, rubber cement, asphaltum, electrical tape, contact paper, and paint. The creative applications are almost limitless.
Rubber cement will stand up to the ferric chloride solution for 5 hours, and PnP paper will stand up to it for more than 3 hours, but permanent marker will begin to break down after 1.5 hours. A batch of ferric chloride is usually good for 5 hours of etching; after that, the etching process dramatically slows.