In 1990, at a prominent U.S. Dental products manufacturing company known as CDI, a unique new liquid was developed with the specific purpose of removing impurities from plastic and metal surfaces. As part of a technical surface preparation process, the aim of the product was to cleanse the surfaces of rigid molds prior to the pouring of refractory highheat silicates. Upon release of this product, the director of CDI, also being a highly regarded numismatist, found that not only did this liquid remove surface dirt, impurities, gums, grease, varnish, inks, etc., But it also quickly removed surface PVC (polyvinyl chloride ?greenresidue?) from coins as well. Not only did the liquid rinse away the PVC, but it did not disturb the metal in any way. Surface ?toning? was left completely intact while contaminants were rinsed off with ease. After repeated tests on different metals and on many surface problem coins, especially those with slime, darkened ash, dirt and wet or dry PVC, the liquid removed residues consistently while leaving the original coin surfaces undisturbed. A collector?s dream remedy. Since the discovery of the cleansing effect this liquid has on coins, the director proceeded to use this liquid treatment before sending off coins for "slabbing" to the certification services. always undetectable. continuously. for over 20 years. Now, after many years of successful use and aiding fellow collectors/dealers with this great product, the developer and manufacturer have agreed to allow its sale to the coin collecting industry. Today, some certification services charge large fees, even a percentage of the coin?s current value to cleanse and remove what this product may do for you at home. Here at cdi we are happy to finally make this product available to everyone with a numismatic passion for coins.