Fabric might lie quiet on the table, but it has direction. That direction is called fabric grain. Fabric grain will determine the way your finished garment falls, stretches, spirals, and matches along seams. Skirts can hang unevenly, side seams can creep forward from center front to center back, or hems can twist when the grain isn’t considered at pattern placement.
It’s common to overlook grain until sewing. A piece of woven fabric is constructed of lengthwise threads, called warp, that typically run parallel to the selvedge. Crosswise threads, called weft or filling, run perpendicular to selvedge at a right angle and from one selvedge to the other. Most sewing patterns have arrows labeled grainline to indicate the grain direction on each piece. You should pay close attention and make sure the arrow is pointing in the proper direction for each pattern piece.
The grainline arrows on a pattern don’t indicate decorative lines in the fabric; you can’t see them. It shows you how the finished garment hangs. That means pattern pieces have to be oriented to the fabric accordingly.
You can’t cut pattern pieces if the fabric is uneven or twisted. Spread the fabric out flat on a table before cutting. Don’t stretch the fabric as it lays on the table; smooth it out as naturally as you would a wrinkled shirt or pair of pants. When the fabric is folded, and the selvedge edges are together, the edges and center fold of fabric should match perfectly, without pulling or warping. If not, you may have twisted fabric in your fabric yardage.
If you have twisted fabric, or a folded edge that isn’t flat, you are just going to inherit the same warped twist and angle as you continue cutting. You’ll see it in pieces that appear to be cut with straight edges, but are actually slightly angled, without noticing.
Here is a simple exercise to help you understand grainline arrow placement:
- Cut two small rectangles, or cut a pattern piece out of your practice fabric (like this simple square shape).
- If you’re not sure how to place a pattern piece, fold the piece of fabric and pin it together. If you’re not familiar with using a ruler, you can cut the piece of scrap fabric into a neat, simple square.
- Measure from the grainline arrow on your fabric to the selvedge at the top of the arrow. Measure again at the bottom of the arrow.
These two measurements should be the same. If they don’t, slightly move your pattern piece and measure again until they match up. Even when you think you’ve cut a piece of fabric with perfectly square edges, there are still times I’ll measure both ends of a grainline arrow on a cut piece. It’s a very simple measuring trick, but it prevents pattern pieces from being angled and cut. You don’t even need the grainline arrow to be perfect; even a small deviation is going to show when you pin a matching side together.
You don’t notice that much of a deviation on the short side of your pattern piece, but that deviation is magnified the further down a longer piece of fabric your cut out piece. Skirts, sleeves, and trousers all hang from the waist or shoulder line. Even a very slight difference in placement will become very visible, and your fabric may twist.
When you place pattern pieces and cut out fabric, always think about how the pieces will hang in their finished state. The fabric grainline arrows will need to be straight and parallel on long fabric pieces, such as skirt panels, tops, and trouser legs; as well as in facings, waistbands, and other pattern pieces that need to match at the seams.
Pin, clip, or weigh the pattern down without moving the fabric. If you’re pinning, avoid pinning too tightly. You want to prevent it from moving as you cut it. Avoid lifting the fabric or cutting while pulling on the edges; the edges will move and skew out of place.
Avoid moving your fabric after the pattern pieces are cut. Lay your fabric flat, and cut it from close to the surface of the table. Don’t lift the fabric off the cutting table. When you cut fabric with a rotary blade, be careful of the layers. Don’t let the fabric move off of your cutting table, or pull the fabric out of position as you cut with the cutting blade. If you’re cutting with a rotary blade on a cutting mat, don’t push or drag the fabric away from your ruler.
Once you cut out your pattern pieces, set aside the right and left front and back pieces, and compare them. Lay your left and right front pieces together as they should appear and compare notches, raw edges, and center fold lines, making sure the two pattern pieces are symmetrical with each other. If they are, they should match perfectly.
Don’t assume that if the pattern piece is aligned with the grain, you’re done. Before stitching your pattern piece, check that they still look aligned after you’ve cut them out and moved them around. Sometimes you’ll see they’ve twisted slightly, or one is cut on the straight grainline, while the other is slightly skewed. It’s much easier to check at the cutting stage before you begin sewing. It’s harder to correct mistakes after the edges have already been sewn, and hemmed. Grainline placement doesn’t have to be perfect, but good grainline placement will help you sew a garment that doesn’t twist once it’s finished.