If you aren't familiar with "check washing", you ought to be. It's a rapidly expanding crime in which thieves steal checks, often from outgoing mail in people's mailboxes, and then apply a chemical solution (we won't reveal what it's made with, but it uses common household products) which can erase ("wash") the desired portions while leaving your genuine signature intact. Typically the "washers" take your payments for utilities, etc., since they're in an envelope that they recognize will probably contain a check. Then they "wash" the desired portions, make the check payable to themselves, and usually alter the check amount. It can prove to be a real nightmare for the victim. The new Check-Guardian Pen now allows you to prevent this from happening to you. Extensive research by Fisher Pen Company (famous for the Space Pen®) has resulted in their new Cellu-Lock" ink technology. This special ink actually creates a molecular bond with the cellulose fibers of the paper, making it impervious to all known fluids used by criminal check washers. And since it's a genuine Space Pen®, it has all the same features found in every Space Pen®, including its unique pressurized cartridge that allows you to write upside-down, underwater, or in extreme temperatures. Ink color: blue.