How to sew a blind hem by hand

To sew a blind hem by hand, turn the hem up along its marked line and work a blind catch stitch: a small stitch that takes one or two threads of the garment and crosses them with a tiny bite in the hem allowance, so the threads form an X between the two layers. Each stitch slants between the allowance and the garment, and the thread barely shows on the right side. The method is common on trousers, skirts and dresses, and it suits most woven fabrics. Knits need a hem that can stretch with the garment, and the crossed threads of a catch stitch, worked with slightly loose tension, suit many of them.

Three things decide how well it turns out: a crisp fold, a stitch that catches very little fabric, and a thread tension that lets the hem lie flat.

Preparing the folded edge

Mark the finished hem length on the garment, then trim the hem allowance to an even width, commonly about 1 1/2 inches (4 cm). Finish the raw edge of the allowance with a zigzag or overlock stitch. The catch stitch works over this single finished edge, so the edge gets only the small fold described below, not a full turn under. A full turn under would put the stitch inside a fold, which is the slip stitch method instead. Turn the allowance up along the mark and press the hemline crease, so the finished edge lies flat against the inside of the garment. The crease sets the length, and the finished edge is what the stitch follows, so both need to be crisp and even along the whole hem.

Check the allowance at several points along the hem, especially near the side seams and the center back, where it is easy to trim unevenly. An allowance that varies by even an eighth of an inch produces a hem that dips or waves, and the catch stitches cannot correct that afterward.

Baste the hem to the garment about 1/2 inch below the finished edge, so the allowance stays where you want it while you sew. Use a single strand of thread matched to the garment, about 18 inches (45 cm) long, which is long enough to work with and short enough to avoid tangling. A fine needle keeps the entry points small and the stitches inconspicuous.

Working the catch stitch

Start inside the hem, hiding the knot in the allowance just below the finished edge. With the hem basted about 1/2 inch below that edge, fold the finished edge back toward the right side about 1/4 inch, so the edge rests against the garment. For a right-hander, work left to right with the needle pointing left. Take a tiny horizontal bite in the hem allowance, just below its edge. Then take one or two threads of the garment a short distance diagonally ahead of that bite, so the thread crosses between the allowance and the garment. Repeat the two bites in turn along the hem, and each pair forms a small X between the layers.

Space the crossings about 1/4 to 1/2 inch (6 to 12 mm) apart, and make each one the same size so the hem looks even. Work steadily along one section at a time, and keep the same direction for the whole hem. Changing direction partway often leaves a visible change in spacing where you switched. Left-handers reverse the direction, working right to left with the needle pointing right. When the hem is done, let the edge fall back so the stitches are hidden.

Keeping the tension right

Tension is the most common reason a blind hem shows. Pull each stitch just snug enough to close the gap between the hem and the garment, but no tighter. A stitch pulled hard leaves a small dimple or puckers the surface, while a stitch left too loose lets the hem sag and can catch on things. Every few stitches, lay the hem flat and check that it sits smoothly. The thread should sit between the hem allowance and the garment, never on the right side.

Knits call for a slightly looser hand. Keep the stitches a little relaxed so the hem can stretch with the garment when it is worn. Before you finish, stretch the fabric gently in several directions, and if the stitches pop or pucker, loosen them before you continue.

If the hem edge looks wavy, the fabric is probably being pulled out of line as you sew. Ease the garment slightly so the hem is not stretched while you work, and keep the catch stitches shallow enough that the outer fabric lies as it did before you started. A small adjustment at this stage saves unpicking later, and it is far easier than correcting a rippled hem after the whole length is done.

Checking and finishing the hem

When the hem is complete, fasten off with a small knot inside the allowance and cut the thread. Press the hem from the wrong side with a pressing cloth, keeping the iron on the hem fold rather than directly over the stitches, so that no shine or impression appears. Then look at the right side in good light. A few small dots of thread are normal, but a visible line of stitches means you caught too much fabric or pulled too tight.

Common mistakes include catching several threads at a time, uneven hem length, skipping the fold press, and using a thread that stands out in color or weight. A hem that will see heavy wear, such as the bottom of work trousers, benefits from a slightly stronger thread. If the garment is valuable or the fabric is delicate, a qualified tailor can often finish the hem with less risk to the fabric. The blind hem rewards patience: once you see how little fabric the stitch needs to hold, the rest of the hem goes faster.