Green Line 2600 1-1/2 in. x 2-5/16 in. Metal Self-Inking Stamp. The first ever self-inking stamps made from up to 80% post-consumer recycled materials are now available in 7 popular sizes. Simply choose any of the following Cosco 2000Plus models of stamps and then choose the Green Line option to purchase the most evironmentally friendly self-inking stamps available: Cosco Self-Inking P20, P30, P40, 2300, and 2600, and Cosco Self-Inking Daters 2360 and 2660.