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 My Pattern Designer Subscriber Newsletter | Volume 15

How Did Pants Patterns Change?

Figure 1:
Older Pants Pattern Draft
 
Figure 2:
MPD 2.5 Pants Pattern
 

There were three fundamental design changes that alter the way MPD pants patterns now draft and you should understand them if you wish to get your own very best pants. They are:

  1. The default amount used for the center back waist dart (CBWD) was changed. This changes the shape of the back crotch curve subtly and that, in turn, affects the shape of the entire pants pattern. Subtly, but importantly.
  2. The default amounts of both front and back crotch extensions were changed. Over the years, MPD has used or recommended a variety of approaches for deriving this amount. With MPD 2.5, we have a new and better method of estimating the default amounts for these values.
  3. Grainline placement. The grainline shows the center of the pants leg. The inseam and outseam are drafted equidistant from this central line, so getting it in just the right place for your body and your measurements is pretty important. The method that MPD has used for many years is illustrated above in Figure 1. The revised method shows in Figure 2.

These five critical numbers (CBWD, front and back crotch extensions, and front and back grainline placement) change the shape of the pants outseam significantly so it better matches the shape of the inseam and has smoother and more gradual curves to it. The effect on fit is quite dramatic.

The new defaults used in MPD 2.5 for these 5 values are greatly improved over what MPD provided in the past. Many users will not need any adjustment or measuring at all for these. Use the defaults and get should get much better pants. For some, though, additional tweaking may be desired to adjust the pants for your personal fit preference. So, all 5 of these values can be adjusted if you choose.

The most unfamiliar of these will be the grainline adjustment. This setting is in the Fit Panel of the Complete Pants Designer tool. The figures below show what it does. Figure 3 is a pair of pants drafted with the grainline at its new default position.

Figure 4 shows what that same pattern and same chart would draft if the grainline is moved 1 inch to the left, towards the center back of the pattern. The crotch curve is distorting and the outseam is bulging between hip and waist. That bulge will not fit well and will be difficult to sew to the front outseam without producing puckers.

Figure 5 shows the same pattern and chart with the grainline moved 1 inch towards the outseam. The outseam is even flatter, but the inseam is now distorting, showing too much of a concave curve. The shape of the inseam and outseam should match as closely as possible. Balanced legs do not twist as you wear them.

Your default may not be perfect. If you get some bulging as seen in figure 4, then you could move the grainline outwards - enter positive numbers to the grainline adjust setting. If your outseam is very flat but the inseam is curved, then adjust the grainline towards center back - enter negative numbers to the grainline adjust setting.

If you do need this adjustment, try large values (an inch is large)  to see what happens, but you will more likely be working with adjustments of a quarter of an inch at a time. A tiny change to this setting can have dramatic effects on the pattern and on your pants fit.

Figure 3:
Dress Shop 8
Default Grainline Placement
 
Figure 4:
Grainline Offset -1 Inch

 
Figure 5:
Grainline Offset +1 inch

 

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