What is indicated by a herringbone or "waffle pattern" on a radiographic film?

A herringbone or "waffle pattern" on a radiographic film is indicative of the film being placed backward during exposure. This pattern is a result of the emulsion side of the film facing outward instead of inward, leading to a characteristic pattern that resembles a herringbone or waffle. This misplacement prevents accurate exposure of the film to the X-rays, resulting in an image with this distinct pattern.

In dental radiography, proper placement of the film is crucial for obtaining clear and diagnostic-quality images. When the film is accidentally reversed, the herringbone pattern appears due to the unique texture and composition of the film's back side, which is not designed to capture X-ray images. This exemplifies the importance of understanding film orientation and proper handling techniques to avoid suboptimal imaging outcomes.