Selecting the correct glass fiber non-woven material requires a deep dive into area weight (gsm), binder type, and tensile strength. For roofing and waterproofing, prioritize high-tensile tissue with urea-formaldehyde or acrylic binders to ensure bitumen compatibility. For surface veils in FRP (Fiber Reinforced Plastic), choose a lower gsm (30-50g/m²) with high resin compatibility to achieve a smooth, corrosion-resistant finish. Always verify the uniformity of fiber distribution, as uneven patches can lead to structural weaknesses in the final composite.