These heavier cards last. If you actually use 3x5 cards handle them multiple times and so on then these are for you. They feel great in the hand and don't fall apart under serious use like in the kitchen.
While I realize that technology often replaces the need for old-fashioned methods of data recording there are times when one just needs to go back in time and use pencil and paper. These are perfect for that and the colors allow for identification of components of information for quick retrieval. No batteries required either!