Selecting the ideal fabric depends on the balance between denier (thickness) and coating type. For lightweight outdoor gear like tents or raincoats, 20D to 70D Nylon Ripstop is preferred for its strength-to-weight ratio. For heavy-duty applications like luggage or tactical vests, 500D to 1000D Nylon (Cordura type) is essential. Always verify the Hydrostatic Head (HH) rating; a minimum of 3,000mm is required for heavy rain protection, while 10,000mm+ is standard for professional mountaineering gear.