Curtesy of the pcgs lingo guide: "tissue toning Color, often vibrant, acquired by coins stored in original Mint paper. Originally, this was fairly heavy paper; later, very delicate tissue. Sometime during the nineteenth century, the Mint began wrapping Proof coins, and occasionally business strikes, in this paper. The paper contained sulfur; as a result, the coins stored in it for long periods of time acquired blues, reds, yellows, and other attractive colors".
Comments
Kyle
"tissue toning
Color, often vibrant, acquired by coins stored in original Mint paper. Originally, this was fairly heavy paper; later, very delicate tissue. Sometime during the nineteenth century, the Mint began wrapping Proof coins, and occasionally business strikes, in this paper. The paper contained sulfur; as a result, the coins stored in it for long periods of time acquired blues, reds, yellows, and other attractive colors".
My coin must have spent a long time in a bag
Brian