AccuFilm I and AccuFilm II For High-Precision Marking AccuFilm I (single-sided) and AccuFilm II (double-sided) have been the standard for marking accuracy for decades. These super-thin (1/1500 of an inch), tough-to-tear films are below the patient's perception threshold, so occlusal marking accuracy is never compromised by a skewed bite caused by an uncontrollable reflex. When you see an AccuFilm mark you can be assured that it's only the high spot you see … and nothing else. So your equilibrations are more precise.