I like the walls in this picture; they look old and dirty with scratches and bug like marks up the wall. It would be good if we could get a similar effect on Gregors bedroom walls to make it look like a bug like creature lives there.

Image reference

https://lh6.googleusercontent.com/-GXetc-ra7vU/TYS0xwSya3I/AAAAAAAAACE/j05tJI3rioc/s1600/3305266424_8a362d88e7.jpg