Pattern grading is the process of creating a range of sizes for a single style.
This isn't something that most people will need to do; but if you're a dressmaker and do bridal wear (for example), or want to design a small line of clothing, you should understand what grading is about.
Women's sewing patterns are generally designed to fit a specific size (usually an 8 or 10). That is the sample size, and the fit is perfected on that sample.
Once the fit is approved for that size, the pattern is "graded" for a full range of sizes (usually size 4 to 18, for misses sizes).
The "grade rules" refer to the amount of change between sizes, for each measurement point. For example, the bust, waist and hip "grade" 1" between sizes for most of the Misses size range.
If you started with a size 8 dress and needed to make another one in a size 10, you'd make the bust, waist and hip 1" larger. You'd do this primarily by making the adjustment at the side seam, and distribute the 1" size difference evenly at each seam.
Since your dress has a front and back, you'd adjust 1/2" each in the front and back. And since the front and back each have a left and right side, you'd divide that 1/2" in half again - so you'd adjust each seam (each side of the front and each side of the back) by 1/4" - the total will be a 1" difference between the sizes. Generally, you do NOT make adjustments at the center front or center back.
The shoulder, armhole, and neck would be made a bit larger also (see the sketch below to get an idea of the difference between a size and and a size 10 bodice).
Similar adjustments are made to the sleeve and skirt, as well as any other styling details (the collar would have to be adjusted to fit the neckline, for example).
The chart below shows a few of the grade rules for a Misses size range. The "+/-" means, for example, if you are starting with a size 8 and are grading to a size 10, you would ADD 1" to that area of the pattern. If you are grading down to a size 6, you would SUBTRACT 1".
You'll notice that the grade rules change as you get into sizes 12 - 16, and again for size 18.
Pattern grading is fairly complex. It's best to avoid it unless it's necessary. Even if you are making a group of garments in a variety of sizes, unless the group of people wearing them are of very similar proportions, it may be easier to fit and pattern each one separately.
However, it's worth learning if you are planning on designing and creating your own clothing line to sell.
The examples on this site reflect MY fitting issues and how I resolved them. YOUR body is likely very different.
But, since this is a site about MAKING patterns and not specifically about fitting, I'm not going to address other fit issues here. And believe me, there are others who can address this issue better than me.
Any of the online classes and books listed below will help you achieve good fit. You can use the techniques on any pattern; but why make the same corrections over an over again? Apply the principles to your block, and the fit corrections YOU need will be automatically built in to every pattern you make!
I can recommend any of the following classes or books to help you achieve good fit, no matter what your size or shape. I have taken some of the classes and own or have used almost all of the books on this list, and have been pleased with how they address fit problems.
I am an affiliate of both Amazon and Craftsy, so I do receive a small commission from the sale of any of the books or classes when you use the links below. You can also go directly to Craftsy or Amazon to order without generating a commission.
||Craftsy offers online sewing classes, including classes that specialize in fit. Two that I'd look into include Easy Fitting the Palmer/Pletsch Way: Shirts & Tops and Sew the Perfect Fit. They also have a fabulous class in altering patterns to fit plus sizes, called Plus-Size Pattern Fitting & Design.|
• Pattern Fitting With Confidence - Written by Nancy Zieman, host of the TV series "Sewing with Nancy". She provides a straightforward, down-to-earth approach to sewing and fitting. Very user-friendly.
• The Complete Photo Guide to Perfect Fitting - I love this book!!! So wonderfully illustrated with photos, using commercial patterns to demonstrate the pattern alterations. It addresses almost any fit problem you might have. So easy to understand and follow!
• Sewing for Plus Sizes: Creating Clothes that Fit and Flatter - A great book for Plus sizes! As a woman gets larger, it's not just the measurements that change - our overall proportions shift, too. This book addresses the different body types and proportions you commonly see in larger women. Truly helpful for larger women.