I think it is so important to feed your creativity as an artist, and creating a post card is a great way to do that quickly and inexpensively. They are small, so if you don't have a lot of studio time, it is a great way to feel like you have accomplished something artistic which is not only beautiful, but also useful. I purchased blank post cards made of heavy water color paper at Asel Art Supply. They have a new location in Denton by the way! You can use water color or any paint on them if you want, but these were done with India Ink and they are lovely.