It is really important that you ALWAYS check that your patterns fit together correctly before going on ahead and cutting your fabric. It may seem a bit tedious checking each seam, but taking a few minutes to check your patterns at this stage can save you cutting out incorrect patterns and wasting precious time and fabric later on .
To check that seams fit together correctly, match them up as if you were sewing them and make sure that they the same length. This is very easy if your patterns don’t have seam allowance (in the case of a block), but if your pattern does have seam allowance, be sure to overlap your seam allowance so that ‘stitching line’ lays on top of ‘stitching line’ – rather than matching up seam allowances (this is when using slightly transparent pattern paper can be very handy!)
I used the bodice block (without seam allowance) for the following examples, but you can use these techniques on all patterns.
To check the shoulder seam, lay your patterns flat and match up the seams as if you had just sewn them together and were now opening up the seam to press flat.
Check that the front and back shoulder seams are the same length. When your patterns are not the same, you will need to add a little to one side of the pattern and remove a little from the other.
To do this, tape some pattern paper to the side you will be adding length to, then measure the excess length and mark the midpoint of this excess. For example, if your front shoulder seam is 6mm longer than your back, half of your excess is 3mm. You will need to remove 3mm from the length of your front shoulder seam and add 3mm to the back shoulder seam. Redraw the seam (the neckline in this case) passing through the midpoint – easing back gradually into the original line.
Sometimes the excess is too much to use the previous method (I’d say if your shoulder is any more than 1.5cm out then use the following method). When this is the case, you need to distribute the excess either side of the seam – half on each end.
Place the seams together and find out the difference between the lengths of the two seams and rather than adding to/removing on just one side of the seam, distribute excess on both ends of the seam (in this case, for example, remove excess at both neckline and armhole).
For example, if your front shoulder seam is 2cm longer than your back, you need to line up your seams so that half of your excess (in this case 1cm) is distributed either side.
Mark the midpoint of your excess on either side (in this example, at the 5mm point on either side) and redraw your neckline and armhole passing through these points, ensuring the line is smooth and eases nicely back into your original lines.
Always check that the armhole is a nice smooth curve (if it isn't it can prove very difficult to sew in the sleeve). Tape paper to the pattern and redraw the line as a smoother curve.
With a basic bodice (or similar) check that the side seams also fit nicely together.
If they are not the same length, repeat steps used on shoulder seam.
Ensure the patterns are matching at one end and then measure the excess.
Mark the midpoint of this excess.
Once again, redraw the seam, passing through the point just marked, being careful to keep the line nice and smooth and the addition quite gradual.
Always check that the hemline comes together smoothly and there are no sharp points. If there is a point at the seam, simply shave off the point by redrawing the hemline with a smooth, gradual curve.
When a pattern is symmetrical always check both ends of the centre line (or "PLACE ON FOLD" line) meet the other seam at a right angle.
Using the bodice block as an example, check that the hemline and neckline are perpendicular to the centre front line. This will ensure a smooth even line when you cut a full pattern piece.