Schlieren imaging, a technique that allows for density variations in transparent mediums to be visualized, was brought to prominence in 1864 and is still in use today. This technique has been used to study supersonic motion in aerospace applications, as well as visualizing airflow in speech. Despite the diversity in application and reference to its use as a leak localization tool, there is no literature supporting its use in composite manufacturing vacuum bags. The purpose of this research is twofold. First, a Schlieren system is developed. Second, a novel method of leakage localization in vacuum bags premised on the use of Schlieren imaging is hypothesizes and the results of the experimentation are presented as proof of concept. An introduction to vacuum bag based composite manufacturing and the importance of leakage localization is provided. The standard methods of leakage detection and localization are discussed and analyzed. The analysis culminates in the identification of the need for a noninvasive, quick, and definitive method of leakage localization. Research around methods of detection satisfying these criteria led to the hypothesis that Schlieren imaging is capable of visualizing flow into a leakage allowing for definitive localization. An analysis of the data recorded during the experiments demonstrates the ability for Schlieren imaging to visualize flow entering a vacuum bag at a leak.