Practical pattern grading techniques for the home sewist.
Pattern grading doesn’t have to be hard! Have you been led to believe that it’s only for industry professionals, or that you need some fancy software or elite knowledge to grade sewing patterns? I’m here to tell you that you can grade patterns at home, easily!
It’s really not rocket science…It merely takes a little bit of sewing know-how and some simple math! Let’s take a closer look.
What is pattern grading?
Pattern grading, most simply put, is the proportional increase, or decrease in the size of a pattern. The purpose of grading is to fit a range of body types and sizes from one base pattern style. Each pattern piece is methodically increased or decreased to create a new size, while keeping the same intended fit, shaping, and proportion of the original base pattern.
Pattern grading should not be confused with pattern alterations. Alterations are the process of making a pattern fit the nuances of an individual body. Whereas, grading is the process of creating a range of new sizes, or a size run.
Important to note: It is important to note that a pattern is not uniformly graded, meaning…the increase and decrease of all points do not uniformly grow or get smaller. The body doesn’t change size in a uniform, even way. Just because my body gets wider, doesn’t mean it gets taller. Make sense? Basically, everything does not equally get larger or smaller because the body changes doesn’t not equally get larger or smaller. Keep reading for more details.
Commonly used pattern grading terminology
Grade – The ‘grade’ of a pattern is the incremental increase or decrease in a pattern size at a given cardinal point. For example; a large majority of commercial patterns will have a 2″ grade. This means that there is a 2″ difference between sizes.
Grading – The process of increasing or decreasing the dimensions of a base pattern style.
Cardinal Points – The points on a pattern where it either increases or decreases.
Base pattern – The original pattern created (usually the middle of the size run). This is an industry term. However, in the home setting…the base pattern would be whatever pattern you are working with. For example, in the ITS Insider Exclusive Library….there are certain patterns that are only offered in 1 size, a size 6. This would be your base pattern.
Trueing – is the process of smoothing and shaping angular and curved lines on a seam to create a nice transition. Trueing includes checking to make sure seam lengths match, corners are 90° angles where necessary, as well as folding darts to create proper seam pattern shape.
Size Run – The sizes included in a specific style. For example; small, medium, large, xl…or, 4, 6, 8, 10, 12.
Cut and Spread | Cut and Overlap – The process of manually grading a sewing pattern by cutting the pattern apart and increasing or decreasing its size.
Pattern Shifting – The process of manually grading by shifting a pattern back and forth to increase or decrease its size.
Pattern Grading Methods for the home sewist
Cut and Spread | Cut and Overlap
The cut and spread|overlap method is the simplest, most accurate, and most intuitive method that you can use at home. Basically, cut and spread or cut and overlap your pattern to create a new size. It really is as simple as that! Of course, you’ll need to determine the amount of growth for each cardinal point and where to draw your cut lines. But, that is it!!! See, easy!
Pattern Shifting
Pattern shifting is the process of shifting the pattern horizontally and vertically along an axis to increase or decrease the pattern size. While this method is seemingly easier… is a little less accurate and a little more tricky to pull off. I prefer the previous method.
Measuring the base pattern style
In order to start grading from a base pattern style, you’ll need to first know the finished measurements so you can determine how much or little to grade. Keep in mind, most patterns already include seam allowance and you need to know the finished measurements of the pattern. To do this, you can simply ‘spec’ the pattern by taking measurements of the pattern to determining the length, width, etc. However, if you grade a commercial pattern, there is no need to remove the seam allowance.
Establishing the grade
To establish the grade, you will need to determine how much your pattern needs to grow between sizes. If you are using a commercial pattern, you can easily see the grade by looking at the back envelope and studying the size chart. If you are not using a commercial pattern, or a PDF pattern, you might have to make up a size chart that makes sense for the pattern you’re working with. So, if your base pattern measures 34″ bust and you need a 40″ bust…the difference is 6″. Then, this 6″ would need to be distributed evenly around the pattern.
Keep in mind that when working with patterns, you will usually be using half of a pattern. So, half of the front and half of the back. All together, there are usually 4 pieces. Remember that when distributing your measurements. They will usually need to be divided into 4 parts. Like mentioned above, if I need 6″ of growth, then I would need to add 3″ to the front and 3″ to the back, right? Technically RIGHT, but….WRONG! I would need to add 1 ½″ to the front and 1 ½″ to the back….Why?! Because I am working with a ¼ of a pattern, remember?!
It is important to note that grading to much (size 2 to size 14) is not recommended. Proportions can get really weird when you try to do that. It is best to grade incrementally, keeping the grading to a 2 or 3 size jump. So, if you wanted to grade a size 2 pattern to a size 14…You would grade the size 2 pattern to a size 8 first. Then grade size 8 to a 14.
Tip: Sometimes a grade is ‘uneven’. For example, a dress might have an uneven grade if the bust grade is 1″ between sizes, and the hip grade is 3″. It is best to keep things simple, and stick to using an even grade. However, if you need to grade an ‘uneven’ pattern, it is best to split the pattern apart at the waist and grade the bodice and skirt separately.
For a more in depth tutorial, check out the Craftsy class on grading.
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