On the Alaska cruise Lindblad Expeditions gave out free postcards.

This one of them. There are three others, if you click the photo above you can see them all.

Two of the cards although beautiful violate one of my rules of postcards that they meet the international size standard to be mailed at the reduced postcard rate. They can be no bigger than about 4 inches by 6 inches.
Lindblad is an excellent tour operator and I highly recommend them for adventure type travel. They have free postcards, excellent naturalist, very interesting guests and delicious food.