This paper presents an assessment of electromagnetic attenuation at the board level over a frequency range of 1 MHz to 8.5 GHz, utilizing two materials: copper, used as a reference, and Continuous Carbon Fibers (CCF), an innovative composite material produced by Fused Deposition Modeling (FDM). Various measurement techniques, including TEM and GTEM cells, Mode-Stirred Reverberation Chamber (MSRC), and near-field probes, were employed to evaluate the attenuation characteristics. Experimental results indicated that while copper offers superior attenuation consistently across the frequency range, CCF demonstrated significant attenuation in specific frequency bands, making it a promising shielding solution. The potential of CCF is further enhanced by its mechanical properties, light weight, and the fabrication flexibility offered by the FDM process. Detailed material characterization was performed, revealing the composition and structural properties of the CCF filament. FEM simulations, coupled with experimental data, allowed for the identification of the most relevant electromagnetic attenuation characterization techniques for this specific test vehicle by confirming the hypotheses established after measurement. The influence of the guard ring design on the overall attenuation performance was also extensively analyzed through FEM simulations, underscoring the importance of optimized via layout and grounding connections to enhance attenuation, with a focus on the waveguide-below-cutoff principle. Furthermore, the simulations enabled the modeling of the CCF material, paving the way for exploring its electromagnetic performance in various applications. This study provides valuable insights for the design of electromagnetic shields using both traditional and innovative materials, offering potential improvements in the performance and versatility of board-level shielding solutions.Read less <