I made a series of collector cards from a drawing series I made that was based of some nicknames given to certain people we knew. There were only 5 copies of each drawing made, making 5 sets of 12 cards, and a couple of the sets were given away to friends. These are my favourites of this set.
There were 3 border colours, red, purple and green, and they were used randomly, so that each card came in different colours to make the sets a bit different.