Synthetic Insulation consists of very fine, tightly woven fibers that form small air pockets to trap body heat. They dry quickly and stay warm when wet. Primaloft and Polartec have worked to create even better compressibility and breathability in the latest synthetic options. Synthetic fill is measured by grams of insulation per square meter and varies from lightweight layering pieces coming in at 40g-60g of insulation up to 150g-200g of insulation for warm belay jackets or upper mountain parkas. Synthetic insulation is best in a wide range of conditions as synthetic fibers will not absorb moisture.\r\nSynthetic\r\n- Stays warm when wet\r\n- Typically less expensive than down\r\n- Measured in grams / square meter\r\n- Have become increasingly compressible and breathable with new technology\r\nDown\r\n- High warmth to weight ratio\r\n- Most compressible insulation type\r\n- Measured in fill power (size of down clusters) and fill weight (quantity of down)\r\n- There are now waterproof downs available