Grading

Pattern Grading is a technique for creating different sizes of a finished pattern.

The initial pattern is created in a base size (not the smallest size), usually a size 10 or size 12. Once the pattern is perfected, the pattern is then made in the other sizes by increasing or decreasing the pattern at set  (or cardinal) points.

There are grading rules to determine how much the pattern is enlarged/decreased at each cardinal point.

Grading allows the one pattern to be made,  then sized up and down, rather than having to remake the pattern in each size from the relevant size Block.

Example

Image 1

This shows how sizes increase from sizes 6 - 20 for the Bodice Block Front. (This example is taken from Bodice Blocks available on this website, to scale).

The measurements increase at certain points in certain increments, though those increments may change at given sizes (e.g. the bust increase is 1 inch from size 6 to 8, but then 1.5 inches to size 12, then 2 inches thereafter).  The increases at other cardinal points are at different percentages - e.g. the increase in the Centre Front is .25 inch.

To make all these blocks you could either make each one individually, or you could make the base size and then use the process of grading to make the other sizes.

Grading is done by establishing a point of reference, or a zero point, for every pattern piece, then all increases (or decreases) are made respective to that zero point. The measurement is increased/decreased at each cardinal point by the relevant amount.

Grading can be done by either computer-based system or manually.

grading-01

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Hi! I'm wondering about the dart intakes, they grow with each size. All I've been taught in patternmaking school, and both my grading books don't discuss this at all. I've only been taught that the dart intake stays the same. I'm wondering where...

Hi! I'm wondering about the dart intakes, they grow with each size. All I've been taught in patternmaking school, and both my grading books don't discuss this at all. I've only been taught that the dart intake stays the same. I'm wondering where this sort of grading comes from, and if there is a book I can read? Thank you so much!
Sanna

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Sanna
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Hi Sanna

Look at attached image No.1. I have placed the blocks differently in relation to each other. (I'm trying to place the darts exactly on top of each other but it is a bit awkward because the dart points are placed further away from the...

Hi Sanna

Look at attached image No.1. I have placed the blocks differently in relation to each other. (I'm trying to place the darts exactly on top of each other but it is a bit awkward because the dart points are placed further away from the bust point the larger the size). However, even though it may look a bit awkward, but the issue should be clear.

You can see that the darts are really the same 'size' (it looks like I made a mistake with Size 6, but all the others are pretty close).

Of course the further out you take a dart, the larger the width at the perimeter. Now look at attached Image 2. The dart marked in orange at CF is quite narrow at the edge as it's a short distance from the Bust Point to the CF, but the blue dart in the shoulder is really large as it's a long distance from the bust point to the shoulder). Of course Figure 2 is looking at darts on one size block, but you should see that the concept is the same.

Basically - as blocks get bigger, they get wider, so as the dart legs extend out further the dart they become wider at the perimeter.

Look at image 3, which is a snippet from a grading textbook - as the sizes get bigger, the darts extend out further and are wider at the perimeter.

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Comment was last edited about 3 weeks ago by Maria Maria
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Thank you so much for that comprehensive answer! I definitely understand now. It makes a lot of sense how you explain it. Thank you for taking the time to educate me

Sanna Myers
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