We group our weights in the following:
super light weight= 1-4oz
light weight. = 5 -10 oz
mid weights = 11 -13 oz
heavy weights. 14 - 17oz
super heavy weights = 18+
light weights are suitable for shirts, accessories, loose pants - skirts. Using light weights on slim fit jeans can cause ripping of fabric or seam slippage.
If you are looking for the best fabric to make jeans, the sweetspot is at the midweights around 12-13oz.. any lighter can be suitable for womanswear and or wider fits.
heavy weight fabrics, 14oz and up are very suitable for jeans, but will be stiffer and need a longer break-in period. Heavy fabrics are also more durable for the obvious reasons.
Fabrics heavier than 17oz will be harder to wear and will not fade as nice, the tend to break quicker due to thicker folds at hips and inside knees.
The super heavy weights can be used perfect for bags