The document provides a method to easily convert between grams per square meter (gsm) and ounces per square yard (oz/yd2) for fabrics by dividing the gsm by 33.906. It also explains that to convert from oz/yd2 to gsm, you multiply the oz/yd2 by 33.906. This is based on the relationships that 1 oz equals 28.3495231 grams, 1 yard equals 0.9144 meters, and 1 square yard equals 0.83612736 square meters. An example conversion shows that if a fabric is 5.5 oz/yd2, its weight in grams/square meter is 5.5 oz/yd2 x 33.906 = 186.483