Tannins and human health: a review. Chung KT, Wong TY, Wei CI, Huang YW, Lin Y. Department of Microbiology and Molecular Cell Sciences, University of Memphis, TN 38152, USA. Tannins (commonly referred to as tannic acid) are water-soluble polyphenols that are present in many plant foods.
How to Cast Jewelry. Jewelry casting is a process of making jewelry pieces that involves the pouring of liquid metal alloy into a mold. It is usually referred to as lost-wax casting because the casting mold is created using a wax model that is melted away to leave a hollow chamber in the middle of the mold.
Metal testing kits come with a set of solutions that rub onto jewelry to figure out the metals and purity of any jewelry. Simply drop the solution onto a cotton ball and rub it against any area of your jewelry. A reaction will change the color of the solution, alerting you to the presence of certain metals.