Athletic wicking knits are a rather broad category of poly/spandex knits designed to wick moisture away from the body. Very popuar for sewing activewear, these athletic knits come in a variety of weights and fiber contents. I will admit I have not yet sewn myself activewear pieces, so my knowledge of these fabrics is limited to this particular one I used.
This space dyed wicking fabric from Spandex World is a medium weight 88/12 poly spandex blend with 60% stretch both lengthwise and crosswise. While it does have a high spandex content, I did not find this fabric to be very supportive. It just doesn't quite "snap" back into place the way milliskin does. However, if you wish to make a sports bra to match a pair of leggings, the support can be improved with the use of a bust sling, and perhaps a firmer lining.
Wicks away moisture from the body, so this is a good option for sports bras. Athletic knits are widely available for making activewear.
Not a lot of support.
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