Typically, the term gobo is reserved for the lens filters and patterns that are affixed to theater lights. The terms flag or cucloris/cookie are actually more accurate for what were going to be using in this post, which is an object placed between the light and the subject, but not attached to it.
For the sake of simplicity, however, Ill use the term gobo to encompass all such modifiers. So, what can you use to make a gobo? Here are some ideas.
As I... more