How to trace sewing patterns without the guesswork

A sewing pattern is rarely just a line on paper. It packs sizes, notches, grainlines, snip marks and sometimes several style variations closely together. Reach straight for the scissors and you'll regret it by your next project at the latest. With our guide to tracing sewing patterns, you keep the original intact and prepare your pieces so that cutting out and sewing go much more smoothly.

With multi-size patterns in particular, tracing pays off every time. You can pick out the right size cleanly, try out alterations directly on your copy and use the pattern again later in a different size. That saves not only paper but also your nerves.

Why trace sewing patterns instead of cutting them out?

Many shop-bought paper patterns contain several sizes that cross over each other in a tight space. If you cut out one size, you lose the other lines. That's a nuisance if, say, you want to sew a dress for yourself first and later for your daughter, a friend or a customer – or if your measurements change.

A traced copy, on the other hand, is free to be worked on: you can lengthen it, shorten it, draw in a different hem shape or add seam allowance. The original stays safe as a reliable template. This is especially handy with pattern magazines, where lots of pattern pieces overlap on one large sheet.

Whether you should trace also depends on the pattern, though. A single PDF sewing pattern that you can print again at any time can certainly be cut out directly for simple projects. For high-quality paper patterns, multi-size patterns and favourite designs, tracing is almost always the better choice.

What you need for tracing

The materials don't need to be elaborate. The main thing is that your paper is see-through enough and doesn't keep slipping while you work. Good options are pattern tissue paper, transparent pattern paper or sturdy tracing paper. Tissue paper is easy to fold and pin, but tears more quickly with very frequent use. Tracing paper is more durable, but a little less flexible.

Also have a pencil or a fine, clearly visible pen to hand, along with a long ruler, pattern weights or tape and, if needed, a French curve. For straight edges, a normal ruler is perfectly adequate. For armholes, necklines or curved hems, a French curve helps, but it isn't a must.

Work on a smooth, light-coloured surface. A large table is ideal, but for long pattern pieces a clean floor can be the better choice. Don't put fabric under the sheet: prints and colours make it harder to see fine lines.

Tracing sewing patterns: a step-by-step guide

1. Check the instructions and size first

Before you trace a single line, read the pattern's size chart. Ready-to-wear sizes and body measurements don't match up the same way with every brand. Depending on the design, the key measurements might be bust, waist, hip or head circumference, for example.

Ideally, measure yourself over your underwear and compare the figures with the chart. If you fall between two sizes, the larger size isn't automatically the right one. For a loose-fitting hoodie the answer may be different than for a close-fitting jersey top. So always take the information on ease and the intended fit into account too.

2. Find all the pattern pieces and markings

Pick out the pieces you need for your chosen variation. A pattern might include short and long sleeves, different collars or several pocket shapes, for instance. The instructions usually state clearly which pieces belong together.

Look closely at the line style for your size. It's often distinguished by dots, dashes or a solid line. Follow it once with your finger before you pick up the pen. That way you avoid accidentally switching to the neighbouring size halfway round a curve.

3. Secure the paper and trace the outline

Lay your transparent paper over the pattern sheet and weigh down the corners. Alternatively, you can use small pieces of tape outside the pattern piece. The paper should lie flat but not be pulled taut.

First trace the outer edge of your size. Work calmly and without pressing hard. On curves in particular, it's worth drawing in short sections rather than making long, wobbly strokes. If a line is hard to see, don't hastily lift the paper. Instead, move the weights one at a time and check the spot in good light.

4. Transfer notches, grainline and labels

Now for the details that will later make or break a good fit. Transfer all notches, snip marks, darts, fold lines, the grainline arrow and any pocket placements. The ‘place on fold’ instruction absolutely has to go on your copy too.

On each pattern piece, note the name of the design, the size, the number of pieces to cut and the fabric side, if given. For example, write: ‘Sleeve, size 40, cut 2 as a mirrored pair’. For pieces cut on the fold, add ‘cut 1 on fold’. This labelling may seem unnecessary at first, but it saves you from mistakes when cutting out.

An important point: not every sewing pattern includes seam allowance. Check the instructions carefully. If they say the seam allowance is already included, trace the line as it is. If it isn't, add it afterwards at the right distance.

5. Add seam allowance neatly

For many garments, 1 cm of seam allowance is a good guideline, while hems often need more. How much makes sense depends on the project, the fabric and the construction. For a delicate viscose dress a narrower allowance can be pleasant, whereas for a jacket or a thick sweatshirt fabric it can be a little more generous.

Mark the desired distance all the way round the pattern piece with a ruler or seam allowance ruler. On curves, it's better to make lots of small marks and then join them into a smooth line. Give the hem the allowance specified in the pattern rather than automatically using the same value as for the side seams.

If you sew with an overlocker, a narrower seam allowance may suit. For a domestic sewing machine and a classic straight stitch, more room usually makes sense. If in doubt, follow the pattern instructions – they're tailored to how the design is constructed.

6. Check, cut out and store

Before you cut out your copy, compare it with the original once more. Are both sides of a symmetrical piece the same length? Are all the snip marks there? Is the grainline pointing in the right direction? Especially on long edges, it helps to spot-check the measurements with a ruler.

Only then cut along the outer line. Afterwards, try not to fold the pieces too small, so you don't end up with stubborn creases. Store them in a labelled sleeve or together with a copy of the instructions. If you sew regularly, this saves you a lot of searching next time.

Avoiding common tracing mistakes

The most common mistake is a missing marking. A single notch on a sleeve tells you which side goes to the front. Without it, you often only notice the difference between similar curves when you're sewing the sleeve in. So it's better to transfer one mark too many than one too few.

Another common one: the line is traced, but the seam allowance is added twice or forgotten completely. Write ‘SA included’ or ‘add SA’ directly on the pattern piece. Then there's no guesswork when you cut out.

With stretchy fabrics such as jersey, ribbing or sweatshirt fabric, the grainline is also especially important. The grainline arrow should usually run parallel to the selvedge. With jersey, the greatest stretch normally runs across it. If you deliberately want to cut across the grain, perhaps because of a striking print, be sure to check beforehand that the garment will still give you enough freedom of movement.

When you want to combine sizes

Many bodies don't fit exactly into one pattern size. Perhaps your bust corresponds to size 40 but your waist to size 42. In that case, you can blend smoothly between the sizes as you trace. Start where the smaller size fits and gradually guide the line over to the larger size.

This works well on side and waist seams. At the shoulder, neckline, armhole and sleeve head you should approach alterations more cautiously, because these areas need to fit together. If you're unsure, sew a toile of a new pattern first from a similar, inexpensive fabric. This is particularly worthwhile for fitted dresses, trousers or jackets.

A handy tip for PDF sewing patterns

With PDF patterns, you don't necessarily have to tape together A4 pages. Large pattern sheets are easier to follow and avoid small inaccuracies at the taped edges. Die Stoffkönigin offers printing of PDF sewing patterns at full size for exactly this purpose. You can then treat the sheet just like a shop-bought multi-size pattern and neatly trace the size you want.

The first time you trace a new pattern, deliberately allow yourself a few extra minutes. A clear copy with complete markings turns cutting out into a pleasant start to your project – and leaves you more room later for the best part of sewing: choosing fabrics, putting them together and wearing or gifting your finished piece.