Modern automotive systems operate at data rates exceeding 16 Gb/s, where small variations in printed circuit board (PCB) materials have a significant impact on signal integrity. One important effect is resin skew, caused by the inhomogeneous distribution of glass fibres and resin within PCB laminates. Differential signals propagating over glass bundles versus resin pockets experience different propagation velocities, leading to timing skew and potential eye-diagram degradation. This internship investigates the measurement-based characterization of resin skew using dedicated, high-speed PCB test structures. The goal is to design, simulate and analyze differential test structures that enable the quantification of skew induced by glass weave and resin distribution. The work contributes to the development of standardized measurement structures for the reliable high-speed interconnect design and material selection.