Indian Head gold pieces was modified by Barber, was "worthy of J.J. Audubon". Dies for the half eagle were sent to the mints in Denver and San Francisco; both western mints reported difficulties in striking the new pieces. Landis wrote to his counterparts at the other mints, advising them that the planchets, or blanks, needed to be shaved very slightly to strike properly. The new coins proved to be thinner than earlier coins of their denomination, due to the field being raised above the design. This meant that automated sorting machines could not reliably sort them when mixed with earlier coins. The new gold
Metal clay used by artists more often than the gold and silver metal clays in the American market place. The actual creation time of a bronze or copper piece is also far greater than that of its silver counterpart. Base metal clays, such as bronze, copper, and steel metal clays are best fired in the absence of oxygen to eliminate the oxidation of the metal by atmospheric oxygen. A means to accomplish this –- to place the pieces in activated carbon inside a container – was developed by Bill Struve. Metal clays are also available as dry powders to which water is