Illustrations for this book are black and white line art.
If you like, it’s nice to add details that are fun for people to color. You can create the line art any way you wish as long as the final image is relatively clean with strong blacks. I personally draw mine in pencil and then up the contrast in photoshop to make a clean final line.
Image size is 8.75 x 11.25″ but with 1/8-1/4″ cut off area inside that. 400 dpi is preferable.
For my personal pages, I paired Japanese ghosts, yokai and mythical creatures with seasonal flowers and often my main character girl. You can pair with flowers if you like, or not! You’re also welcome to draw my main character girl in with the monsters if you like. No pressure to do so, though. Main character girl is a noodle cart girl, Edo era.
For reference on Japanese ghosts and yokai, yokai.com and hyakumonogatari.com are good sites!
My only main restriction is that the monsters or ghosts shouldn’t be too modern (no godzilla), think more Edo era or older, like folklore monsters. And the images shouldn’t be too gross or sexual, to keep the overall book being relatively PG and open to more audience. So no butt-hole-eye monsters or naked boobie monsters, please!
Here’s some pages from the book below, no need to do in my style, your own style is awesome.