It is Kate’s commitment to use as many recycled products as possible. She regularly visits local recycling centers to search for rough material that she sees potential in. The scrap copper has typically come from the electrical and roofing industry, manufacturer cast offs, refrigerator coils, and stamping machine negatives.
United States pennies produced before 1982 were 100% copper. These coins can be manipulated using heat and other techniques in ways that modern pennies cannot. Kate occasionally also uses wheat pennies minted between 1909 and 1956.
The "Mercury Dime" was minted from 1916 to 1945. The image was designed as the Winged Liberty Dime, but gained its nickname as a misnomer because of the image being confused with the Roman god Mercury. These coins are composed of 90% silver and 10% copper.