Requirements: A deck of cards, glue, a band/hack saw, too much free time.
Glue each card of a deck together, and slice a small strip off of the desired side with a band saw or hack saw once the glue has dried (not too thin, for fear of inaccuracy). If you require a thin material, use an image editing program and make a template. If you want it to look even more authentic, try getting it printed at staples or somewhere with high-quality printing services.