The hem rolls up at the edge

Short answer: Single knit jersey always rolls at a free edge. That is the nature of the fabric rather than a fault, and steam or an extra line of stitching keeps it flat.

Why jersey rolls

In single jersey the two faces of the fabric are knitted differently. The tension is therefore uneven, and a free edge always rolls towards one side. A bottom hem rolls upwards, and vertical edges roll towards the wrong side.

What the maker can do

An edge can be secured with a turned hem and double stitching, with a ribbed edge or with tape on the inside. That costs fabric and time, which is why rolling edges appear most often on the thinnest and lightest garments. See bamboo tops for women.

How to make the edge lie flat

Steam the edge and press it flat under light weight while it cools. That holds for a day or two. For a lasting fix, an alterations shop can add a fine line of stitching. Never cut the edge off, because the new edge rolls too.

When it is a fault

If only one side of a garment rolls, or the seam pulls at an angle, the making is at fault. If all free edges roll the same way, it is normal jersey behaviour. See bamboo t-shirts for women and bamboo dresses.

Frequently asked questions

Does interlock roll as well

No. Interlock is knitted the same on both sides and lies flat on its own.

Does ironing help

Only briefly. Steam and light pressure last a little longer, but the edge returns.

Does it get worse over time

Slightly, because the fabric softens. On the other hand the roll gets less tight.