Spreadshirt Golden Ratio Fibonacci Spiral Men's Jersey T-Shirt In geometry, a golden spiral is a logarithmic spiral whose growth factor is . The golden spiral can be found in the tiniest sub-atomic particles of the microcosm to spiral galaxies of the macrocosm. If you love the science of aesthetics, then this MADE IN THE USA - This T-shirt is perfect for that tailored look. Throw it on under a sweater or sweatshirt, or wear it by itself with a pair of jeans or khakis. GREAT QUALITY T-SHIRT - 100% fine-combed jersey cotton (except for heathered colors). Fabric weight: 4.3 oz (lightweight). Durable double-stitched bottom hem and stretchable cotton collar for lasting comfort. OFFICIAL SIZING (width x length measured in inches) - S (18" x 28") | M (20" x 28.5") | L (21.5" x 30") | XL (24" x 31") | XXL (25.5" x 32") | 3XL (28" x 33.5"). For best results and to maximize durability machine wash cold, inside out and tumble dry