RCW 19.84.010: Redeemable cash value to be printed on face.

No person shall sell or issue any stamps, trading stamp, cash discount stamp, check, ticket, coupon or other similar device, which will entitle the holder thereof, on presentation thereof, either singly or in definite number, to receive, either directly from the vendor or indirectly through any other person, money or goods, wares or merchandise, unless each of said stamps, trading stamps, cash discount stamps, checks, tickets, coupons or other similar devices shall have legibly printed or written upon the face thereof the redeemable value thereof in cents.