This study comprehensively investigates the effectiveness of three advanced sample preparation techniques—ion milling, laser cuttingLaser-based techniques, and Focused Ion Beam (FIB) milling—for high-resolution imaging of Euplectella aspergillum sponge fibers called spicules. Primarily composed of silica layers with nanometer-scale organic interlayers, spicules possess complex hierarchical structures which are critical for their mechanical propertiesMechanical property. Accurate characterizationCharacterization of these structures requires advanced sample preparation to prevent artefacts and preserve structural integrity. Ion milling introduced significant surface degradation and uneven material removal in spicules. Despite its precision, laser cutting caused thermal damage and induced micro-cracks, compromising the microstructural integrity. In contrast, FIB milling provided superior results, producing smooth, artefact-free cross-sections with minimal thermal and mechanical stress. The real-time imaging capability of FIB milling further ensured optimal sample preparation, making it the most suitable technique for delicate biological materials like spicules. The findings of this study provide valuable insights into the preparation of biological samples for further research and analysis.