Is the Spanx OnForm Low-Back Tank worth it?

If you need smoothing under a low-back dress and already have a bra that works with it, yes. It does one job well. If you want an all-in-one shaper with support, look elsewhere.

Does it have a built-in bra?

No. It is a shaping tank only, so you need a separate bra, ideally a low-back or convertible style that stays hidden.

How does it fit compared with a regular tank?

It runs snug by design. Spanx advises sizing by your measurements rather than your usual top size, and the firm fabric takes some effort to pull on.

Can I wear it under a light-colored dress?

This listing is black, so it can show through thin or pale fabrics. It is safest under dark or opaque clothing.

How should I wash it?

Machine wash cold and line dry to keep the compression fabric from stretching out. Skip the dryer and fabric softener.

Spanx shaping pieces tend to drop during seasonal sales and holiday promotions. Watch the price history rather than buying at full price if you can wait.

What do buyers say about the Spanx OnForm Low-Back Tank Top?

Rated 4.1 out of 5 from 28 ratings.

Spanx OnForm Low-Back Tank Top

4.1

Last price we saw

$29.00at Spanx, last seen Nov 2

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Our take on the Spanx OnForm Low-Back Tank Top

The Spanx OnForm Low-Back Tank Top is a shaping tank designed to smooth the torso while leaving the upper back open for low-back dresses and tops. It uses Spanx's OnForm stretch fabric for firm compression across the stomach, waist and hips, with a scoop front and a low-cut back. It is a pull-on layer, not a bra, so it works best under clothing that already has its own support. The latest listed price is for the black 1XL, and it sits in the middle of the range Spanx shaping tanks usually sell for, so it is not a markdown moment.