Jersey or 2x1 rib — the choice that decides fit
Jersey tank tops are cut from a flat knit: they drape, they show the body, and they are cheap. A 150–180gsm cotton jersey tank is the shape most promotional buyers mean.
2x1 rib tanks are knitted with a rib structure that stretches across the body and recovers. They fit closer, they do not cling in the wrong places, and they cost more per piece because rib knitting is slower.
The mistake is buying a ribbed look at a jersey price. Ask which structure, because "cotton tank" covers both and the fit is not interchangeable.
The armhole and strap: where a tank is won or lost
Armhole depth decides whether the garment reads as a vest, a muscle tank or a cami. Deep armholes need a wider strap or the whole thing collapses sideways; a narrow strap on a deep armhole is the single most common reason a bulk order is rejected on fit.
Binding versus a turned-and-stitched edge is the second difference. Binding holds the armhole shape through washing; a plain turned edge waves after a few cycles and cannot be pressed back.
Ask for the armhole depth and the strap width as numbers, not as a photo. Those two numbers are the specification.
- Strap width 3–5cm: standard vest.
- Strap width 6cm and up: muscle tank, needs a shallower armhole.
- Binding at armhole and neck: holds shape, costs more, visible after three washes.
Weight, and why a heavy tank is not automatically better
At 140–160gsm a tank is a summer promotional garment: cheap, cool, and translucent in white. At 180–200gsm it holds shape and can be sold retail. Above 220gsm the fabric is heavier than the garment needs and the armhole starts to gape, because the weight pulls on a narrow strap.
For a white tank sold at retail, 180gsm combed cotton is the practical floor. Below that, the fabric shows everything and customers return it.
The three reasons a bulk tank order comes back wrong
Armhole depth drifting between sizes, because the pattern was graded on chest width alone. A tank has to be graded at the armhole and strap as well, or the size run is inconsistent even when every individual piece matches its measurement chart.
Shrinkage on a light jersey, which is proportionally larger than on a heavy tee: a 150gsm tank can lose 5–7% in length, and a short garment losing 7% becomes cropped.
Colour showing through on white and light heather, where the same fabric at 180gsm would be opaque. Buying the cheapest weight for a white colourway is how a program ends up with returns.
What a quote should state
Structure (jersey or 2x1 rib), weight in gsm, armhole depth, strap width, binding type, and the size run by measurement. Those six lines are enough to compare two quotes; a photo and a price are not.