A 3-step checklist for flat pattern fitting adjustments

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I think the most challenging part of sewing your own clothes (and even more so for other people!) can be the fitting of the garment, rather than the actual construction.

I have a 3-step checklist for what I call the 'pre-fit': checking my body measurements against a pattern's measurements to see what obvious flat pattern adjustments I might need to make, before I even make a toile. This checklist mainly applies to patterns for woven fabrics, for fairly fitted styles where the shoulder seam sits at the shoulder (rather than dropped shoulder), and the fit is close at the relevant parts of the body (bust, waist and/or hip).

The three checks are:

  1. Shoulder width
  2. Bust point placement
  3. Circumference (bust, waist and hip)

(For sleeved garments, I also recommend checking the sleeve length and bicep circumference!)

Before we get started, remember that if you're using a pattern with seam allowance included, you should draw in your stitching lines inside the pattern edge (i.e. draw inside each outer edge as if removing the seam allowance). When you take measurements on the pattern to compare to your body measurements, you want those to be without seam allowances.

For ease of reference, I've also shown some of the alterations on a small-scale version of our bodice block pattern.

The Pre-fit:

Shoulder width

What to measure

Measure from the base of your neck to the end of your shoulder. There is usually a small dip, dimple or depression at the end of your shoulder (at the top of your arm), if you raise your arm and bring it slightly to your front, rather than straight up at the side. This is what you should use as the marker for the end of your shoulder.

Compare this measurement to the width of the shoulder on the front bodice piece (not the back shoulder, which often contains a dart or additional ease).

Flat pattern adjustments

If the pattern's shoulder measurement is wider than yours, you may need a narrow shoulder adjustment. Conversely, you may need a broad shoulder adjustment if your shoulder measurement is wider than the pattern's.

I usually only need to make a small narrow shoulder adjustment, and I've shown the easy method I use below. If you're making an adjustment of roughly 3/4" or less, you can use the method below without needing to adjust the sleeve caps - yay!

  • Draw lines as shown below in red. The vertical line runs parallel to the grainline, from roughly halfway across the shoulder. On the back pattern piece, try to place your vertical line so as to avoid the back shoulder dart if there is one.The horizontal line is perpendicular to that line, and which should cross the armscye just above the notch. Cross front and cross back lines can be a convenient guideline for the horizontal line, if your pattern has them. 

  • Cut along the red lines. Move the cut piece horizontally by the amount of the required adjustment. For a narrow shoulder adjustment, move the piece inwards, towards centre front or back (overlapping the pattern piece as shown below on the front bodice pattern piece). For a broad shoulder adjustment, move the cut piece outwards, away from centre front or back (as shown on the back bodice pattern piece below).
  • Tape the cut piece down in its new position, and draw new lines to blend across the jagged part of the shoulder and armscye seams. Aim for these lines to cross the middle of the jog/step in the original seams.
Narrow shoulder:

Broad shoulder:

Bust point position

What to measure
  • Apex to apex: measure horizontally between the peaks / bust points. Then divide this measurement by two. Compare it to the horizontal measurement between the apex and the centre front line (the red arrow on the pattern picture below).
  • Apex to waist: measure vertically from one apex down to the waistline. Remember, when taking measurements, you can easily mark your waistline by tying a length of narrow elastic around your waist. Compare your apex to waist measurement to the corresponding measurement between the bust point and the waist line of the pattern (the blue arrow on the pattern picture below).
  • Shoulder to apex: measure diagonally from the centre of your shoulder to one apex. Compare it to the corresponding measurement on the pattern (the green arrow on the pattern picture below).
    Flat pattern adjustments
    • Move the waist dart horizontally: you may find you need to move the waist darts horizontally, if your apex to apex measurement (when halved) differs from the pattern. If your halved body measurement is smaller than the corresponding pattern measurement, move the waist dart closer to the centre front by measuring across from each dart tip/point, and drawing a new dart by joining up the new points (as shown in red on the picture below). If your halved body measurement is bigger than the corresponding pattern measurement, move the dart away from centre front. You may also need to redraw the dart tip of your bust or side dart, moving it by the same amount as the waist dart. Reconnect the dart legs with new lines to the new dart tip.
      • Move the bust point and darts vertically:
        Shoulder to apex: Draw a box around the bust dart and apex, as shown in the image below, and cut it out. Move the box up or down (without moving it horizontally) by the amount required to make the shoulder to apex measurement match yours. Tape it down, over a spare piece of paper, and draw smooth lines to connect the side seam across the gaps.
        (Alternatively, you can draw lengthen/shorten lines on the pattern roughly where the dashed green line is on the image under 'apex to waist' below, and lengthen or shorten the pattern piece there. You would then need to lengthen the pattern between the bust point and the waist, roughly where the blue dashed line is on the same image, to keep the overall front bodice length unchanged).

      • Apex to waist: The blue dashed horizontal line on the image below shows a suggested position for the lengthen/shorten lines for this adjustment. If you need to increase or reduce the pattern length to match your apex to waist measurement, draw corresponding lengthen/shorten lines on the pattern and adjust the pattern length there.

      Separately, if your cup size differs from the cup size the pattern was drafted for, you might need to make a small bust adjustment or a full bust adjustment. Check out these helpful summaries by Seamwork of how to make these adjustments for four types of bodice pattern (those with no darts, bust darts, four darts and princess seams):

      Circumference (Bust, Waist and Hips)

      If your pattern is a 'nested' pattern (showing multiple sizes nested together), you may be able to account for differences between your bust/waist/hip and the recommended body measurements for the pattern size, by grading up or down to the size which matches your body measurements.

      However, if this isn't an possible, an alternative is to add or remove width at the side seam, and/or tweak the waist darts.

      What to measure
      • Bust: Your full bust measurement, going around the fullest part of your bust, under the arms, and across the back.
      • Waist: Measure the circumference of your body, around your natural waist. To make it easier to identify your waist, you can tie a length of narrow elastic around your waist. Compare this to the assumed waist body measurement for the pattern size you have selected.
      • Hip: Measure the circumference of your body, around the fullest part of your hip. Patterns usually assume this is 8-9" below the waist line. Compare this to the assumed body hip measurement for the pattern size you have selected.
      Flat pattern adjustments

      Once you know the total adjustment amount (the difference between your body measurement and the assumed measurement for your selected pattern size), you should divide it by four, since each pattern piece corresponds to half the front or half the back, and you will adjust both front and back pattern pieces. An adjustment of 1/4" made to the front pattern piece and the back pattern piece will result in a 1" total adjustment.

      You can reduce the waist by drawing a new point at the waist seam that is closer, by the quartered adjustment amount, to centre front or back. Then draw a new side seam connecting the original underarm and hip points to the new waist point on the side. The blue line in the picture below shows a waist reduction.

      Similarly, you can increase the waist by drawing a new point at the waist seam that is further away from centre front or back, and drawing in a new side seam going through that point. The green line in the picture below shows an adjustment to increase the waist.

      Alternatively, if you only need a small reduction, you can widen or narrow the darts slightly. For example, moving each dart leg, on the front pattern only, by 1/8" will adjust the waist by 1/2" in total. T

      You can decrease or increase the hip measurement by adjusting the side seams in the same way as the waist seams, as shown below. 

      Similarly, you can adjust the bust by bringing in the side seam, or making it wider, in line with the bust  point. (This is a separate adjustment from full/small bust adjustments, which are covered above. Use this where the cup size is correct for you but you are just in between pattern sizes). Since you can usually choose a pattern size for a bust measurement within 1" of your actual bust measurement, this should ideally only need to be at most 1/4" adjustment on each pattern piece.

      If you need to adjust more than one of the bust, waist and hip in this manner, simply mark all the new points first, before drawing a new side seam to go through all of them.

      That's a wrap!

      Do you have a go-to set of adjustments you make before you really get started with a project? If not, maybe try these and see how you get on!

      drafting

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