Pixiq

Tape the back of the metal with packing tape. Use a piece of Styrofoam to float the piece in the acid. Image side showing and as it is suspended in the water so, the metal falls away.

With safety glasses and gloves, pour the ferric chloride into the tub, until your piece floats. As the piece is etching takes place it create bubbles and this is when ventilation is crucial. (I use a container that is sealed (pyrex glass for example with cover to float the metal on the acid).

You can write the time the etching will be done on the styrofoam. Etching should take about 20- 45 min, depending on the depth of  the etch you desire. Check the metal every 20 minutes by rinsing and checking with your fingernail. When done place in distilled white vinegar to neutralize and rinse with water thoroughly.

Clean the metal with Scotchbrite or brass brush, then you can use an oxidizer to blacken the piece to help the lines pop out. (Or you can take Sharpie and rub it over the areas quickly to get a similar effect).
 

 If you want to learn more about this, Ganoskin.com is a free metals web site that posts articles and has a message board where you can ask questions. This is my process that works for me, there is more than one way to do something and always more to discover….You can even just draw on metal with a sharpie. The Sharpie acting as a resist will also protect the metal surface. This is a beautiful example of this below, done by artist Jim Albertson, whose work is in my new book, Digitial Image Transfer: Creating Art With Your Photography. The bird was a graphic image ironed on and the graphic underneath was found on the Internet. As always, ever art.