If you are looking for a simple index card holder that you can place on a desk, there are a few options to choose from. The simplest and cheapest of them is a U-shaped acrylic cardholder. It is not the prettiest cardholder out there but does the job well enough. Then there are acrylic card pockets that have a bit sleeker design. However, some people might not like the plasticky feel of acrylic. There are a variety of metal options for them, including stainless steel and aluminium cardholders.