****I am looking for the best index cards available, and in the process tried these out. These are called Oxford Esselte Pendaflex; in some places they are only called by one or two of these labels, but they are all the same card. They are much more expensive than others, so I had high hopes for them.PRO: These cards are absolutely fabulous for fountain pens. No feathering, no deep absorption (with subsequent widening) of line of ink into the paper. My work involves exclusively fountain pens, and it is hard to find a card to accommodate them. The surface of the card is not coated, so it works with any type of pen or marker, and I am delighted with this.CON: The cards are not as thick as I'd hoped. They are not flimsy, just thinner than other index cards. I couldn't find any info about whether or not they yellow with age, so I think they probably do.I think that these are still pretty good index cards and if you don't mind that they are a tad thin, you will be pleased.Recommended.****