A visible trail that is left by or indicates a projectile's flight path. The most common example is the glowing trail of speeding bullet, which in real life is done by firing tracer ammunition. (see post #6371369)

This applies to any form of projectile (e.g. [[arrow (projectile)|]] on post #6271456 or [[throwing knife|throwing knives]] on post #4981382), and somehow can be rendered as a subset of [[speed lines]]. 

h1. See also
* [[motion lines]]
* [[Tag Group:Image Composition]]