starch passport / ticket

A letter with a postmark can be sent all over the world,a mark on the tourist combined with Bar code also be used as a ticket which can travel in the tourist spot.Also the ticket will never be lost.The mark is made by starch,so that it would disappear as the time goes by.The period is 12 hours.We will only need to gently lift our hands, it will be a more convenient and interesting ways to make our ticketsbe checked.