Below is just a quick post about using a child’s finger print to make an etching. I’ve done this before. A most perfect grand parent gift. I first cut out some small pieces of nickel-silver. You could use copper, brass, or other metals. I just had some nickel silver laying about left over from other projects.
First we cut out some small hearts from some paper. These were to be used as stencils. The student places the stencil on the metal and then dips a finger in a tar solution. Then the student will dab his finger into the heart, thereby creating a heart shape with the finger prints effectively cordoned off from the rest of the metal by the stencil.
Here you can see the student placing his dipped-in-tar-finger onto some paper, to practice the motion. The tar will resist the eventual acid bath, showing the finger print. The rest of the metal is eaten away with the finger print remaining.
In the pics above you can see me holding the metal and stencil in place while the student dabbed his tar laden finger onto the metal. The heart shape gives the student a place to aim for and makes the finger prints into a recognizable heart shape.
The rest of the process is pretty much a standard etching/jewelry making process. I taped off the sides to create a border and I taped off the backs to keep the backs uneaten by the acid, which only eats away at the metal. I used Ferric Chloride for the etchant/mordant, which takes a while, (8 hours or so) but is pretty non-toxic. With the students’ help I finished up the pieces by drilling, sanding, adding the black background, and more general finishing.