To test the stretch percentage of any fabric, take a fabric square 10 cm x 10 cm or grab a section of the fabric you want to test that is 10 cm wide, use my free PDF stretch gauge to help you calculate.
It is important to note which grain you are stretching first, so mark the weft, this goes from left to right and the warp, this runs parallel to the selvedge.
Take the fabric and fold in half if you are working with a cut piece, do not stretch on the cut edge.
Now stretch the fabric until you feel it wants to spring back, don’t over stretch. Make a note of the stretch percentage of the weft first and then the warp. Also it is important to note if the fabric returns to its original length. Fabric that does not have good recovery is not suitable for lingerie or tight fitting garments as it will become baggy and ill fitting very quickly!
For example – The weft of my sample piece stretched from a cut square of 10 cm to 14 cm and the warp to 12 cm. weft grain travels around the body so this perfect that it has more stretch. Therefore the stretch percentage of the fabric is 40% in the warp and 20% in the weft. Now I also know my Direction Of Greatest Stretch (DOGS) and my Direction Of Least Stretch (DOLS), important information in lingerie making!
Hope this helps,
Nicola x