Staring at a tangle of lines and triangles? How to read a sewing pattern comes down to a few markings: cutting lines, grainlines, fold lines and notches. Learn those and the rest follows.
This guide is part of our series on sewing for beginners.
| Item | What to know |
|---|---|
| Cutting lines | Each size has its own line style: dotted, dash then dot, or varying dash lengths |
| Notches on front pieces | Standard to use single notches |
| Notches on back pieces | Standard to use double notches |
| Common seam allowance (metric) | 1 cm |
| Common seam allowance (imperial) | Half inch, about 1.25 cm |
| Bias direction | 45º angle to the selvedge |
These figures come from The Creative Curator’s pattern guide. Conventions differ between pattern companies, so check the key in your own instructions before you rely on them.
Start with the envelope and instruction sheet
Before you touch the tissue, read the instruction sheet. It holds the key to that company’s symbols, which is the one place you can trust over any general guide.
Look for these things first:
- The size chart, so you match your measurements to a size rather than your shop-bought size.
- The fabric suggestions and the amount of fabric needed for your size.
- The list of pattern pieces and which ones you need for your chosen view.
- The cutting layouts, which show how to place pieces on your fabric.
Tick off the pieces you plan to use. It saves you from cutting something you never needed.
What do the lines on a pattern piece mean?
Some patterns show cutting lines; others show seam lines and require you to add seam allowances before cutting. Many patterns print several sizes on one sheet, and each size gets its own line style, such as dotted, dash then dot, or varying dash lengths. Pick your size, find its style in the legend, and follow that line on every piece.
Some patterns are printed one size per sheet, or let you choose layers to print. That leaves fewer lines on the paper and you are less likely to cut the wrong one.
The stitching line sits inside the cutting line, and the gap between them is your seam allowance. Some patterns are made with a 1 cm allowance and others with a half inch, which is about 1.25 cm. The pattern may not state this on the piece, and it can differ from one section to another, so check the instructions. Our guide to seam allowance explained covers how to measure and mark it.
Grainlines and fold lines
The grainline is a long straight line with an arrow at one or both ends. Place the piece so this line runs parallel to the selvedge, the finished edge of the fabric. Measure from the line to the selvedge at both ends and adjust until the distances match.
The other grains matter too:
- The cross grain runs at a 90º angle to the selvedge. It is rarely marked, because the grainline already keeps the piece in the right direction.
- The bias is fabric cut at a 45º angle to the selvedge. It has more stretch and drape.
Some pieces have a fold line instead of a grainline. It marks the edge to place on the fold of your fabric, and that edge has no seam allowance because there is no sewn seam. You cut the piece once and open it out to get a symmetrical, full-size shape.
Notches, dots and other markings
Notches are matching points. You line them up when you join pieces, so that a sleeve meets the armhole or a side seam meets its partner at the right spot. It is standard to have single notches for front pieces and double notches for back pieces.
Most commercial patterns draw notches as little triangles. Some older pattern companies point them outwards, while most indie designers point them inwards. If a notch extends past the edge of the piece, you can cut the triangle outwards as well.
Other markings you will meet include:
- Lengthen and shorten lines, where you adjust the piece to fit.
- Darts, which shape fabric around the body.
- Gathers, tucks and pleats.
- Pocket, button and buttonhole placements.
- The bust point.
Transfer these to your fabric before you remove the paper. Use fabric-safe chalk or a washable marker for internal markings; reserve tiny snips for edge markings within the seam allowance. A placement mark for a closure is a good example, and the guide on how to sew a zipper shows why accurate marks help there.
Mistakes beginners make when they read a sewing pattern
Skipping the pattern instructions can lead to cutting or assembly mistakes. The paper looks simple, but each mark carries an instruction, and missing one can change how the finished piece hangs or fits.
- Ignoring the grainline. A piece cut off grain can twist, hang badly or stretch where it should not. Always measure to the selvedge instead of guessing by eye.
- Cutting the wrong size line. When lines overlap, it is easy to drift onto a neighbouring size. Trace your size or run a highlighter along it first.
- Forgetting the seam allowance. Check whether your pattern includes it. Trimming it off by habit leaves you with a garment that comes out too small.
- Skipping the notches. Without them, curved seams, sleeves and gathered edges are much harder to line up.
- Placing a fold-line piece flat. If you cut it as a single layer, you end up with half a piece and wasted fabric.
If a symbol is not clear, go back to the key on the instruction sheet. If it still is not, compare the marking with the diagram in the step where it is used, since the drawings often show what the words leave out.
Using the cutting layout well
The cutting layout is a small diagram that shows how to arrange the pieces on your fabric. It tells you whether the fabric is folded, which way the pieces face, and which pieces are cut more than once.
Find the layout that matches your view, size and fabric width. Then work through it in order, placing the largest pieces first. Pay attention to shading or labels that show which pieces go face up and which are flipped.
If your fabric has a one-way print, a nap or a pile, all the pieces should point the same direction. Read the layout notes for that, because they often have a separate arrangement for such fabrics.
A simple routine before you cut
- Read the instruction sheet and find the symbol key.
- Choose your size and trace or highlight its cutting line.
- Check the cutting layout for your fabric width and view.
- Lay out the pieces, matching each grainline or fold line to the fabric.
- Cut along the correct line and mark notches, darts and dots.
- Keep the paper pieces until the garment is finished, so you can check a marking later.
Take your time over the first pattern. Reading carefully now saves unpicking later.
Frequently asked questions
What do single and double notches mean?
Show answer
Single and double notches commonly distinguish front and back positions; match corresponding notches when joining pieces, including front-to-back seams. Match them as you pin.
Do I cut the line or beside it?
Show answer
Check whether seam allowances are included. If included, cut on your size’s cutting line; otherwise, add the specified allowances before cutting.
What is a fold line?
Show answer
It marks the pattern edge that goes on the fold of the fabric. That edge has no seam allowance.
Are symbols the same on every pattern?
Show answer
Not always. Check the key in your pattern’s instructions, because companies and indie designers vary.
