Here is an example of graffiti I am talking about for pins and bracelets. Thing is I dont yet know about how much detail will work well. Seems to me not too much...
https://farm8.staticflickr.com/7922/46334274045_e8e934eae5_b.jpg
Come to think of it I probably wont use that because it seems to be permanent on a private wall on a public sidewalk.
Here are some pictures I took weeks ago that have already been painted over and dont exist anymore...
https://farm8.staticflickr.com/7816/47145829041_d86c3c47d0_b.jpg
https://farm8.staticflickr.com/7922/40180821903_08214bcd22_b.jpg
https://farm8.staticflickr.com/7871/46422385764_8307b14be8_b.jpg
https://farm8.staticflickr.com/7912/47102193451_61967e2844_b.jpg