The painting grouping got me thinking about how popular and inexpensive it is to use book pages, especially botanicals, to create gallery artwork for a large wall. Here are a few pictures of botanical groupings found through google images. With some inexpensive Ikea frames and a used book, you can have a gallery of art for a steal.
Apartment Therapy did a post on their favorite botanical books for framing. Jenny of The Little Green Notebook wrote about botanicals on black paper. Grace from design*sponge points out that the New York Public Library's digital gallery offers free printable art, and Erin from Elements of Style recommends Panteek for botanical images.