The Vacuum Assisted Process (VAP) can achieve better laminate quality than other infusion processes. This study aims to develop void characterization tools, to characterize the resultant void content in VAP, and to evaluate various membranes with respect to laminate quality. Infusions were made with each membrane and either single- or double-sided distribution media coverage. Each laminate's thickness gradient was measured, as well as the void content by three methods for comparison. The voids' position and size were characterized. The ultrasound attenuation and the shear strength were correlated to the local void content.