RE: Official RCSkydiving questions & help
In general, the lower the porosity the better the chute performs. All of the real chutes made of zero perosity are the top of the line chutes. 100% of all the air has to go around the zero perosity, 5% means 5% of the air can go through the fabric. Most of the guys do not like sewing zero perosity because it is extremely slippery.