Use these instructions to find the stretch percentage of your fabric. This is important for getting the best fit out of your clothing.
First, collect your fabric and a ruler.
Then, fold your fabric under by a few inches, so that you are not stretching along a cut edge, but rather a folded one. This helps your fabric not warp while stretching.
Now, with your left hand, hold your fabric down at "0" on your ruler, and hold the fabric with your other hand at 5 inches.
Now, stretch the fabric with your right hand along the ruler, until the fabric is tight but not warped.
What number does the fabric reach?