| Ring ShapesIf the vehicle that drops the oil is slow moving or stationary and the ground is level, the oil will diffuse into an almost perfect ring. As the lighter elements separate and flow outward these will take on the appearance of a bulls eye, flower or ring nebula (supernova remnant in real life).
|
| Cometary and Meteor ShapesSimilar to a ring, but the ground is sloped or cambered. As the oil separates, it flows downhill with the lighter elements moving faster on a thin film of water. This creates a "tail" that resembles a comet or meteor. In addition to the example shown here, the image at the top right of this page is a prime example.
|
| Splatter ShapesHere the vehicle is moving faster and/or leaking more heavily so it trails a succession of closely spaced drops that have a splash or splatter pattern.
|
| Miscellaneous ShapesThese are usually broader expanses that are more free form. There is a slightly deeper film of water with oil eddies on top. This gives the whole thing a more 3-dimensional look with softer edges.
|
