I love illustrator ^o^
The brushes are fun to use in illustrator, and I find it easier to vector in it and file sizes are so much smaller than photoshop ones xD

Anyways, here's a sumi keiichi wall, and this one was made in both illustrator and photoshop. I made the swirly/painted lines in illustrator, then I stuck it in photoshop and made the rest of the wall. The texture is from http://www.desktopanime.com/

Here are versions without the texture




I hope you like it =D