I was playing with a new black light. This time a flourescent tube type. It works great even in daylight. I found Belterra $1 chips with and without the security mark. Also a $1 Argosy with the vertical mark. I didn't have others to see if they ran horizontal like the 50 cent chips. The new 25 cents are marked, but I didn't see a mark on the one $5 chip I had.