I desperately needed index cards to organize my recipe files and these worked out perfectly I color coded my recipes according to appetizers desserts meats parties...
I bought these cards to make flashcards for a class. They're so thin that you can see the writing on both sides when holding them up. Other cards I've bought seem to be similarly thin which makes using them as flashcards less than optimal. I remember using index cards in school thaat were very thick and wonder if they've just stopped making these. These cards were also quite expensive. I got a pack of 200 cards which were similar in quality from the 99 cent only store. Can't say there was much difference. I would recommend buying the cards that come in a little notebook that can be ripped out if you are looking to use them as flashcards. Being able to see the writing on both sides renders these pretty much useless
I use these for many things: mailing list notes to self notes to customers. The bright colors change as I work my way through the pile marking the time I wrote the note or took the address.