Custom Self-Inking "ECO" Stamp - Impression Dimensions: 1" x 2-1/2". These ECO green self-inking stamps have all the great benefits of our traditional P-Series but are constructed with 54% recycled content. The EP13 stamp can either have its ink replenished by adding additional ink to the stamp pad, or you can choose to replace the stamp pad. Use ClassiX Refill Ink only.