Humans always create economic exchange systems or some sort, and there are always humans who are judged by other humans to be in need of restraint.  Throughout the world prison authorities have tried different systems of controlling the economic transactions of the people in their custody, and these attempts have produced plenty of collectible tokens, chits, etc. for the delectation and amusement of those of us who are subject to a lesser degree of official oversight.

USA, CALIFORNIA, Department of Corrections, California Men's Colony, Inmate's Canteen Yard Card, 8/90, I have these in pink, gray, yellow, & peach, XF/+ @ $8.50 each
Click picture for enlargement.

Bob Reis
POB 26303
Raleigh NC 27611
phone: (919) 787-0881
(8:30AM-10:30PM EST only please)
fax: (888) 503-8308
how to order