I have several hundered cards in my collection. and i collect every varity that is every collectors decision. i have several 4 queens collections. of Gangsters. Base ball players, Sands Rat Pack etc. also color variations. some are very distinct. if it looks different i collect it. have not bought the book on slot cards yet. i have been collectiong the cards since the very begining. and have purchased 2 big collections. So it is every collectors choice. What ever makes him happy.