This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
The method described in the following produces a very good metal stamp for any name, initial, drawing, etc.
Procure a smooth and perfectly level sheet of brass about 1/16 in. thick and about 3 by 4 in. in size. Nickelplate the brass so that the copper deposit will not stick to it. If a small plating outfit is not at hand the piece may be plated at a local plating works for a nominal price. Dip the plate in melted paraffin until the coating is about 1/16 in. thick and see that no metal is exposed. Drill a hole in one corner and attach a wire.
Draw the letters or sketch desired, using a metal stylus having a sharp point, taking care to make the lines scratched in the wax clean and open to the surface of the metal (Fig. 1).
A large open-mouthed bottle or glass tank will be required for the plating solution, which is made by dissolving copper sulphate in water until the solution is saturated with the sulphate and then adding a few drops of sulphuric acid. Immerse the plate in the solution as shown in Fig. 2 and connect with the zinc pole of the battery. Put a piece of pure copper in on the opposite side of the jar and connect with the carbon pole of the battery, using care in each case to keep the connection of the wire and the upper part of the plate above the surface. One or two dry cells will be sufficient. If the current is right, the deposit on the waxed plate will be a flesh pink; if too strong, it will be a dirty brick color and the plate will have to be washed and the current reduced. When the desired thickness of metal is deposited, remove the plate and pour boiling water on the back. This will remove the thin copper shell and the nickeled plate may be laid away for future use.
Procure a flat pan and after placing the shell in it, face down, sprinkle a little resin or soldering flux on the back. Lay three or four sheets of the lead from tea packages on the back of the shell and heat it over a spirit lamp or on the stove until the lead melts and runs into the crevices on the back of the copper, thus making it solid and suitable for mounting. Mount as shown in Fig. 3 with small brass screws and after polishing the surface to remove dirt, etc., the stamp is ready for use.