Global Base Layer Market Size, Share & Demand Report By Product Type (Tops, Bottoms, Full Body Suits), By Material Type (Synthetic, Natural Fibers, Hybrid Materials), By Functionality (Moisture-Wicking, Thermal, Compression, Anti-Microbial, UV Protection), By End User (Men, Women, Kids), By Distribution Channel (Online Retail, Specialty Stores, Supermarkets/Hypermarkets, Brand-Owned Stores), By Application (Sports & Outdoor Activities, Military & Defense, Industrial Workwear, Everyday Wear) By Region & Segment Forecasts, 2026–2031