7 Easy Ways To Finish Raw Edges of Fabric: Expert Tailor’s Guide

A cut edge is a row of threads with nothing holding the end of them. That is the whole problem behind every seam finish, and it is why the same four or five techniques have been reprinted in sewing books for a century. The threads a blade severs lose their neighbours, the wash pulls them loose, and the loose end works its way back toward the stitching line until the seam has a bald patch beside it.

There are seven finishes worth knowing, and every one of them solves that problem a different way: some trap the threads under stitch, some shorten them, and some hide the whole edge inside a fold so it can never fray in the first place. Choosing between them is not a matter of taste. It is decided by the weave of the fabric, how much seam allowance you have to spare, and whether the inside of the garment will ever be seen.

This guide covers all seven with the settings, the allowance each one needs and the point where each one fails. The numbers are the part most guides leave out, and they are the part that decides whether a garment survives the third wash or can be let out when it no longer fits.

Why Raw Edges Fray, and Which Fabrics Do Not Need Finishing

Woven fabric is two sets of threads crossing at right angles. When you cut across them, the outermost threads in each direction are only held by friction where their neighbours used to interlace. Nothing stops them sliding out.

Three things decide how fast that happens. The tighter the weave, the slower the fray, which is why a good quilting cotton loses a millimetre or two over many washes while a loose linen or a tweed can shed half a centimetre on the first. The finer and more slippery the fibre, the faster it travels: silk and viscose escape quickly, cotton and wool hold on longer. And the more the garment is washed, the faster all of it happens, because agitation is what drags the loose ends out.

Knits are a different structure. They are loops, not crossings, so a cut edge curls rather than unravels. That is why a jersey T-shirt hem can be left raw and simply curls under, and why a raw edge on sweatshirt fleece, felt, or a bonded fabric is a deliberate design decision rather than an unfinished seam. It is also why pinking shears, which exist to shorten woven threads, are wasted on a knit.

The fingernail test before you choose a finish

Before you commit a fabric to a finish, cut a 2 inch square from the corner of the yardage and drag a fingernail firmly across the cut edge a few times.

• Threads that barely move: tightly woven cotton, poplin, calico. Pinking or a zigzag is plenty.
• Threads that pull out to 3 mm or more: linen, tweed, loose canvas. Machine-finish it, and prefer an enclosed finish.
• Threads that pull out in handfuls, or the fabric is so sheer it distorts: a bound edge or a French seam, and handle the pieces as little as possible.

The same test tells you whether pinking will work at all. If the loose threads are longer than the sawtooth is deep, the shears are decoration, not a finish.

Which Finish Eats How Much Seam Allowance

This is the table nobody publishes, and it is the one that decides what you can do with the garment two years later. A pattern gives you 5/8 inch (16 mm) of allowance. Some finishes use a few millimetres of it and leave the rest intact; others swallow all of it.

The practical consequence: if the garment may ever need letting out, children’s clothes, anything tailored or anything expensive, use a zigzag, an overcast stitch or a bound edge, all of which leave the allowance usable. A French seam or a flat fell is a commitment. It gives the cleanest inside in the business and it cannot be undone without recutting the piece.

Step 1: Zigzag Stitch: The Default for Woven Fabric

If you only learn one finish, learn this one. Almost every machine made in the last fifty years has a zigzag, it needs no special foot, and on a woven fabric it will outlast the garment.

The setting matters more than the technique. A width of about 3 mm with a length of about 2 mm is the starting point for medium cotton and linen. Widen to 4 mm and shorten to 1.5 mm for a loose weave that sheds badly; narrow to 2.5 mm and lengthen slightly for a fine poplin, or the edge will pucker into a stiff cord.

1. Trim the seam allowance to a level 3/8 inch (10 mm) first. A ragged edge cannot be finished evenly, and you want to be zigzagging a straight line, not a staircase.
2. Set width 3 mm, length 2 mm, and sew a 4 inch test on a scrap of the same fabric. Look at the edge, not the top: the thread should wrap over the cut edge on the right-hand swing.
3. Position the work so the right-hand swing of the needle falls just off the fabric, about 1 mm beyond the cut, and the left-hand swing lands about 2 mm inside it. On most machines the edge of the presser foot or the innermost marking on the needle plate is the guide.
4. Sew the full length of the seam allowance at a steady pace, then trim any whiskers of thread that stick out beyond the stitching with small sharp scissors.

If the edge tunnels, that is, the fabric dips and puckers between the two legs of the stitch, the stitch is too wide for the cloth, the tension is high, or you are pulling the fabric. Narrow the width by half a millimetre, drop the top tension one number, and let the feed dogs move the fabric. A strip of tear-away stabiliser under a very fine fabric also stops it.

One limitation is worth knowing before you rely on this everywhere. Zigzagging the two seam allowances together, as many tutorials suggest, seals them in one pass but welds the seam shut. You can no longer press it open, and on a fitted garment that changes how the seam sits on the body. Zigzag each allowance separately if the seam should open.

Step 2: Overcast Stitch, and the Overlocker If You Own One

The overcast stitch does the same job as a zigzag with better manners. It combines a short straight segment that bites into the fabric with a zigzag segment that loops over the edge, so the threads are anchored rather than merely crossed. Most machines built since the 1980s have at least one.

Work it with an overedge foot if you have one. That foot carries a small bar or pin on its right edge, and the stitch forms over the bar so the loops slide off the fabric without curling it. Without the foot, guide the cut edge to the same point on a standard foot and accept that it will take a little more care.

An overlocker, or serger, does the whole job in one pass: it trims the allowance, wraps the edge in two, three or four threads, and sews at several times the speed. Two things are rarely said about it and both matter.

First, the knife eats allowance. Serging a 5/8 inch allowance removes 3 to 4 mm, so the finished seam allowance is narrower than the pattern intended. Sew the seam first, then serge outside the stitch line, or serge the flat pieces before construction and never trim past your seam line.

Where there is no machine at all, how to hand sew seams covers the overcast and blanket stitch that do the same job by hand.

Second, differential feed is the setting that decides whether the edge lies flat. On a knit, raise it to about 1.3 so the feed holds the edge back and stops it stretching into a wave. On a fine woven that puckers, drop it to about 0.7. Leave it at 1.0 for medium wovens and canvas and it will behave.

Step 3: Pinking Shears: The Only Finish With No Machine

Pinking is the fastest finish there is and the weakest. The shears cut a sawtooth, which leaves the threads at the edge at different lengths; a thread can only unravel as far as the nearest point of the tooth that holds it. That genuinely slows fraying. It does not stop it.

The rule for whether pinking is enough: pink only fabric where the fingernail test pulled threads shorter than the depth of the sawtooth, and only where the garment will not be washed hard. Quilting cotton, calico, poplin and lining fabric are all reasonable. Linen, tweed, canvas and anything destined for weekly washing are not.

1. Cut the seam allowance to a level 1/2 inch (12 mm), leaving more than the sawtooth depth beyond the seam line so the teeth never bite into the stitching.
2. Lay the fabric flat on the table, not held up in the air, and keep the blades perpendicular to the edge so the teeth are even.
3. Cut in one firm, continuous squeeze rather than nibbling, and work in one direction along the edge. Two layers at once is fine on light cotton and will strain the handles on anything heavier.
4. Press the pinked edge flat. Heat sets the cut threads and flattens the whiskers, and it makes more difference than most people expect.

Two things worth knowing. Pinking leaves a shadow: on a light, fine fabric the sawtooth shows through as a slightly darker line along the inside of the seam, which is why it is a poor choice for sheer or pale silk. And think twice before adding a stitch line inside a pinked edge to “secure” it, as some guides instruct. Pinking plus a stitch is belt-and-braces on a cloth that barely frays and wasted effort on one that does not: if the edge needs a stitch to hold it, skip the shears and zigzag it instead.

A rotary cutter with a pinking or wavy blade does the same job and is easier on the hands on heavy fabric, provided you have a mat under it.

Step 4: Turned and Stitched: The Clean Finish

This is the finish that hides the raw edge entirely inside a fold, and it is the neatest thing you can do on a light or medium woven without a serger. It is also called a clean finish, a fold-over finish, or a flip and sew finish.

1. Press the seam flat first, so the allowance behaves while you fold it. Work on the wrong side.
2. Turn one seam allowance under by 1/4 inch (6 mm) and press the fold with the tip of the iron. Turn it under a second time by the same amount and press again, so the raw edge is buried inside the double fold.
3. Edge stitch about 2 mm from the inner fold, all the way along the seam, and backstitch at each end.
4. Repeat for the other seam allowance, then press the finished seam flat or to one side as the garment needs.

Two variations are worth keeping. Turning once and stitching gives a quicker, lighter finish that leaves the raw edge visible inside the fold, fine on fabric that barely frays. Topstitching each folded allowance from the right side instead of edge stitching it turns the finish into a visible design line, which is how workwear and children’s clothes are often made.

The limits are bulk and curves. Two double folds on each side of a seam add around 12 mm of thickness, which is nothing on cotton lawn and a ridge on wool coating. And the fold will not lie flat around a tight armhole without clipping. On a curve, clip the allowance at intervals of about 12 mm before folding, and press over a ham rather than a flat board.

Step 5: French Seam: For Lightweight Fabric Only

A French seam is not a finish applied to a seam; it is a different way of constructing the seam so that both raw edges end up enclosed. It is the tidiest inside in garment sewing, it needs no special equipment, and it is only suitable for lightweight and sheer fabrics.

The construction order is the point, and it is the thing most published guides get wrong. The first pass is sewn with the wrong sides together, which puts the raw edges on the outside. You then trim, turn the piece right sides together and sew again to trap them inside. A guide that tells you to start with right sides together has the order inverted, and if you follow it you end up with the raw edges on the inside where they fray undisturbed.

1. Place the fabric wrong sides together and sew a 1/4 inch (6 mm) seam. Lightweight cotton, silk habotai, voile, chiffon and organza are all in scope.
2. Trim the allowance to about 1/8 inch (3 mm) with small sharp scissors, and trim the corners at the ends of the seam. This trim is what makes the finished seam narrow.
3. Press the seam as sewn to set the stitches, then fold the piece right sides together along the seam line, press the fold, and sew a second pass at 3/8 inch (10 mm), enclosing the trimmed allowance inside.
4. Press the finished seam to one side. French seams are not pressed open.

Because it is a way of building the seam rather than a finish applied afterwards, the order of the two passes has to follow the same logic as any basic seam, which how to sew two pieces of fabric together walks through from the first stitch.

The second pass must be wider than the trimmed first pass, or the raw edges escape. And the method needs the full 5/8 inch of allowance to work: the first pass at 1/4 inch plus the second pass at 3/8 inch is exactly 5/8, and the trim happens between the two. It is a poor choice for thick fabric, for a seam that curves tightly, and for anything you might want to let out later.

Step 6: Flat Felled Seam: The Denim Standard

A flat fell is the strongest seam in common use and the only one that also looks finished from the outside. It is why jeans survive years of washing: the raw edges are folded inside a doubled seam and held by two rows of stitching that take the stress off any single line of thread.

It needs a sturdy fabric and the full 5/8 inch of allowance, and it is a commitment. There is no unpicking it. Use it on denim, canvas, twill, wool coating and workwear, and not on anything light, sheer or bulky enough to make the fold a lump.

1. Place the pieces wrong sides together and sew a 5/8 inch (16 mm) seam, then press it flat.
2. Trim the underneath allowance only to 1/4 inch (6 mm). Leaving the upper allowance full width is what gives you something to fold.
3. Fold the wider allowance over the trimmed one so it wraps it completely, tuck the cut edge of that fold under by about 3 mm, and press the fold hard.
4. Edge stitch 2 mm from the folded edge through all the layers, then sew a second parallel line 6 mm from the first if the fabric is heavy. Press flat from the wrong side.

On the outside a flat fell shows as a raised band with two parallel lines of stitching. On the inside there is nothing but a fold, which is why it appears on the inside leg of jeans and on the yoke of a work shirt. Weave it into a lightweight fabric and the band dominates the garment, so match it to weight, not to ambition.

Step 7: Bound Edge: Bias Tape and the Hong Kong Finish

Binding is the decorative option, and the only one that gives a clean edge on a fabric too fragile, too fray-prone or too loosely woven for anything else. A strip of bias-cut fabric is wrapped around the edge and stitched down, so the raw edge is covered on both sides by tape.

On an unlined garment, the seam allowance is often interfaced as well as bound, so that the tape has something stable to sit on; what is sewing interfacing explains which weights suit which cloth.

Bound edges come in three grades of effort. The simplest is a folded bias strip bound over a hem or an unlined jacket edge. The second is a Hong Kong finish, which binds the seam allowance of an unlined garment, it is a seam finish and not a hem, and gives the inside of a jacket the neatness of couture. The third is a full bound quilt edge, which is the same technique at four times the length.

1. Cut the strips on the true bias, at 45 degrees to the selvedge, and join them on the diagonal so the seams do not add bulk. Bias stretches around curves; a straight-grain strip ripples on them.
2. Press the strip in half lengthwise, then open it and align its raw edge with the raw edge of the seam allowance, right sides together.
3. Stitch in the fold of the strip using a 1/4 inch (6 mm) seam. For a Hong Kong finish, keep the strip narrow, around 1 inch (25 mm), so the finished binding is slim.
4. Wrap the strip around the raw edge to the wrong side, press, and stitch in the ditch of the first seam or edge stitch along the binding. Check both sides: no raw edge should show through.

How much binding a square of fabric gives you

The arithmetic is simple and almost nobody publishes it. A continuous bias strip cut from a square yields a length of about the square’s side squared, divided by the strip width.

A 12 inch square, cut into 2 inch strips and joined into one continuous length, gives roughly 72 inches of binding: 144 divided by 2. That is enough to bind about 1.8 m of edge once it is folded. A 10 inch square at 1 inch strips gives about 100 inches, which is plenty for a jacket’s inside seams.

Cut the square a little larger than the sums suggest and make a sample: every join where you sew two strips end to end costs you about a strip width of length, and the figure is close, not exact.

Watch the Finishes Being Sewn

The first video works through six seam finishes on a normal machine with no serger in sight, which is the closest thing to watching this whole article happen in order.

The second sets the two enclosed finishes side by side, the French seam and the flat fell, which is the clearest way to see why one suits chiffon and the other suits denim.

The Mistakes Worth Avoiding

Most of what goes wrong with edge finishing goes wrong before the machine starts. Six mistakes account for nearly all of it.

• Finishing after assembly instead of before. A long flat seam allowance on a table is easy; the same allowance inside a nearly finished sleeve is not. Finish each piece before you join it wherever the construction allows.
• Leaving the cut edge ragged. Zigzagging a staircase produces a staircase of frayed threads. Trim level to 3/8 inch first, then finish.
• Stitching a pinked edge to “secure” it. The sawtooth is the finish. If the edge needs a stitch line to hold, it needed a zigzag in the first place.
• Using one stitch length for everything. A 1 mm zigzag on medium cotton makes a stiff, tunnelled cord. Start at 3 mm wide and 2 mm long, and adjust from the test scrap, not from a chart.
• Forgetting to press. A finish that is not pressed never sits flat in the garment, and pressing after stitching is what sets the threads and flattens the bulk.
• Choosing a finish that eats the allowance. A French seam or a flat fell on a child’s garment removes every millimetre you might need to let out. Match the finish to whether the garment can be altered.

What Each Finish Fails Like After Washing

Every finish has a characteristic failure, and knowing it makes the fault easy to diagnose months later.

The last row is the one to take seriously. Fabric glue, fray check and iron-on tape all have a place, a quick repair, a decorative edge, a costume that will never be washed, but they stiffen the fabric where they sit, they can stain pale cloth, and a needle will struggle through a glued seam if you ever need to alter it. On a garment, a stitched finish is the only one that survives laundering with its drape intact.

One test settles every argument about a finish: sew a 6 inch sample, finish it exactly as the garment will be finished, and put it through the same wash and dry cycle you will use on the finished piece. Two washes tell you more than any chart, and it costs five minutes and a scrap.

Frequently Asked Questions

Conclusion

Seven finishes, one decision. Trap the threads with stitch, shorten them with a blade, or hide the edge inside a fold. Every method in this guide is one of those three ideas wearing different clothes. A zigzag will carry most wovens through years of washing, a French seam will make the inside of a silk blouse worth looking at, a flat fell will outlive the jeans it is sewn into, and pinking will save you ten minutes when the fabric is tight and the teeth are deep enough to matter. What none of them will do is compensate for a ragged edge, a stitch that misses the cut, or a seam that was never pressed.

Tell us in the comments, and if you have a fabric that has defeated every finish you have tried, say what it is; that is usually a weave problem, and there is a combination in this list that will hold it. Which finish do you reach for first, and is there one you have quietly given up on because it never worked the way the tutorials promised?

About This Guide

Written and sewn by Mithu, who has finished the seams on everything from silk habotai to 14 oz denim, who owns a serger and still zigzags most seams because it is faster to set up, and who once pinked a whole linen dress before discovering that linen is exactly the fabric pinking cannot save.

The settings, allowances and stitch widths in this guide follow standard machine and pattern figures, and every one of them can be checked against your own machine manual, your pattern’s seam allowance and a scrap of the actual fabric before you commit the good piece.

All images in this article were created using AI.