Stretch and release as a quick test
Short answer: Pull the fabric across and let go. If it springs back, the item holds its shape through the day. If it stays stretched out, the item will give as you wear it over the course of the day.
How to do the test
Hold the fabric with both hands about ten centimeters apart and pull moderately, the way you would stretch an ordinary item in everyday use. Let go and watch what happens in a single second. This is a test you can easily do in a shop without anyone noticing.
What the two outcomes mean
If the fabric springs straight back to its original width, elastane is present, and the item returns to its shape after a full day of wear. If the fabric becomes wider and stays that way, the item gradually gives, which shows up most clearly around knees, elbows and waist.
Where it matters most
The test matters most for underwear, leggings, socks and anything else close fitting, since they need to follow the body's movement all day. See bamboo leggings for women and bamboo underwear for women , where good stretch is the difference between a comfortable day and one spent constantly adjusting.
Where it matters less
In loose items and sleepwear, the test matters far less, since the fabric is not meant to sit close to the body anyway. See bamboo sleepwear for women as an example, where comfort and softness weigh more in the judgment than stretch itself does when you hold the item in your hands.
Test several spots on the item
Repeat the test at several spots on the same item, not just one. An item can have good stretch in the middle of the back and less near a seam or edge, where the fabric is sewn to another piece, and that is exactly where it gives first in wear.
Compare with an item you know
If you have an item at home that you know holds its shape well after many washes, use it as a reference when testing something new. That makes it easier to decide whether a stretch is good or poor, instead of relying only on a feeling in the moment.
The test does not say everything about durability
Good stretch says something about shape, but not everything about how long the fabric lasts overall. So also look at weight and surface when judging an item, to get a fuller picture than stretch alone can give you on its own.
Test it again after a few washes
If you already have an item at home, repeat the test after a few washes to see whether the stretch has weakened. A fabric giving less resistance than when it was new is good to know before you buy more of the same kind.
Frequently asked questions
Does a lack of stretch mean poor quality
No, not necessarily. It usually just means the item is meant to be loose rather than close fitting. Always judge stretch based on what the item is meant for, not as an isolated measure of quality on its own.
Can you see elastane on the item's label
Yes, it is usually listed as a percentage on the care label. Two to five percent elastane is common in underwear and close-fitting clothes, while loose items often skip it entirely without that being a problem.
How hard should you pull during the test
Moderately, like an ordinary movement in everyday life. The test should show what an ordinary day does to the fabric, not what a hard, full-strength tug would do to that same piece of fabric.
You can find the full range at Bamboo-Clothing.com.
