White horses remind me of my Grandpa. When I was a child and we saw a white horse, he said it was good luck. He showed me the custom of stamping to get the good luck. My Grandpa is the only person I ever knew who licked his thumb when he saw a white horse. I am guessing he learned it when he was a child in Illinois.
Container: EasyLunchBoxes
Left Side: White Horse – cheddar garlic mashed potatoes cut with a cookie cutter, Eye – dried blueberry, roasted broccoli
Top Right: Pistachios
Bottom Right: Blueberries
Eclectic Lamb 
My grandma, from Texas, always stamped white horses for good luck. She was born about 1895.
Very interesting! My Grandpa was born in 1918.
My grandmother did this and we continue to do so. I am trying to find out when or where the custom started My grandmother was born in 1905.