Difference between Flat Thank You Card and Enclosure Card

[andyodell]

As far as I can see the same size, paper etc. But a different price. Unless there is something that I am missing.

Im making some thank you enclosure cards that can be put in with customer orders but don't know which is the best product.

[randysgrandma]

I would consider a business card. It is small and you can put a business description on the back. I think it would be more likely to be kept.  

[andyodell]

Thanks, I already have some business card size ones. I was just really wondering what the difference between these to are.