Wash. Const. art. XII, § 11

No corporation, association, or individual shall issue or put in circulation as money anything but the lawful money of the United States. Each stockholder of any banking or insurance corporation or joint stock association shall be individually and personally liable equally and ratably, and not one for another, for all contracts, debts, and engagements of such corporation or association accruing while they remain such stockholders, to the extent of the amount of their stock therein at the par value thereof, in addition to the amount invested in such shares.

The legislature may provide that stockholders of banking corporations organized under the laws of this state which shall provide and furnish, either through membership in the Federal Deposit Insurance Corporation, or through membership in any other instrumentality of the government of the United States, insurance or security for the payment of the debts and obligations of such banking corporation equivalent to that required by the laws of the United States to be furnished and provided by national banking associations, shall be relieved from liability for the debts and obligations of such banking corporation to the same extent that stockholders of national banking associations are relieved from liability for the debts and obligations of such national banking associations under the laws of the United States.