Grading Complex Styles pt. 2

Part 2 of this series continues the discussion of how to grade complex styles. It is not necessary to have the Handford book to understand the concept, but some experience with grading would be helpful.

This part of the series was going to contain a lot of explanation with lots of examples. There are two reasons that I held off on that. The first is I am considering writing a book on the subject. I am sure it will be a best seller and I will be able to retire early [eye-roll]. The second is that it would be impossible to discuss every possible scenario. It would be best to explain the principle and let you work out your specific grading problem on your own. You will benefit with having to struggle with the material and learn lots in the process.

Just a side note, these pieces have been simplified, no darts or extra gathers. I am also ignoring the seam allowances. The grading is done the same way regardless. This demonstration only shows how to figure out a length grade. The same principle works for widths.

Anyway, let's move on to the examples....

In order to grade a complex style, you need to have basic blocks that are already graded. On top I have a basic block that is already graded. Below that is my ungraded pattern pieces for a bodice with a mid-riff.

There are many ways to determine the total length grade. In this case, I just want to know what the length difference is between the graded basic block and the ungraded pieces. I want to grade my pieces up to the next larger size. To do this, I just lay the ungraded pattern pieces on top of the next size and align the pieces along the horizontal and vertical axis. My drawings are missing the horizontal, but you can pretend there is a line that runs from the side-seam/armscye points across the pieces. BTW if you would rather, you can figure all this out mathematically....

Once you know the length grade difference, you can then decide where you want that length growth to occur on your ungraded pattern pieces. In the examples below, you can have that length split between the two pieces or all of it in one piece or the other (shown in red).

The question you have to ask is:

This is where the beauty of computerized grading happens. I can play with the grade as much as I want - plugging in different numbers until the proportions look the way I want for each size. Hand grading would be a little more complex. The more complex the style, the more difficult the grade can become when doing it by hand. Handford's suggestion to tape the pieces together with long strips of tagboard can work in hand grading. The grader will have to determine if additional grade points should be added and how much movement should occur. This can be done by using Handford's red lines of distribution. Sophisticated manipulation at each grade point can only occur in CAD.

Still the principle works the same regardless of how complex the style or method.

1. Determine your total length/width grades.
2. Calculate the length/width difference between sizes at the grade points.
3. Decide where the growth should occur by comparing the total grade and the difference between each size at the needed grade points. What proportionally looks correct? How is my fit affected?

Grading Complex Styles pt. 1

Part 1 of this grading series will make more sense if you have a copy of Jack Handford's Professional Pattern Grading book. Unfortunately, the book is now out of print. Still, this entry may be helpful in grading complex styles, especially part 2...

An anonymous reader left this comment:

I love your blog. Thank you so much for all the information. I've recently started grading patterns. I can grade simple styles by following Handford or other books' steps no problem. But when it comes to complex designs, such as clothing that has unusual shapes and consists of multiple panels, I have trouble placing the "distribution lines" (red lines in Handford's book) on the patterns. Handford suggests by putting the patterns on the mannequins and draw the red lines. But sometimes it isn't practical as I'm using a CAD program.
Any suggestions?

This is a good question and can be confusing. The first thing I had to do was go back and look at Handford's book to see those red lines. Sometimes when I read a technical book my eyes glaze over and I skim until I find the info I am looking for. To be honest, I have had to study Handford's book several times to grasp what he is saying. In any event, I couldn't recall those red lines....

The red lines are illustrated on page 1-2 of Handford's book. He uses the red lines to indicate where a pattern grows or shrinks. The rest of the book has more illustrations of basic pattern pieces that show this. The key is to read page 3:

Obviously the cutting and spreading or overlapping of each part of each pattern to grade it one size up or one size down would be far too time consuming and invite much chance for error to be practical.

In other words, a grader could draw those lines of distribution on each pattern piece and then cut the pattern apart to spread or overlap them for the next size. He is absolutely right that such a task would be extremely time consuming, error prone and tedious. This is the failure of the Price/Zamkoff book on grading because this is how they explain grading. It was the primary reason I was so confused about grading too. If you were to grade by hand, could you imagine making duplicate copies of your base pattern so you could cut it apart? You would then need to carefully align the pieces, tape them securely, redraw the pattern, and cut it out. Then you would have to start the whole process over again for the next size. Yikes!

I don't mean to be so hard on Price/Zamkoff because they explain the concept of grading correctly. The problem is that it is not practical, even in a CAD environment.

I am not sure why Handford places those red lines in his illustrations other than to illustrate where the growth is occurring as you grade using his method. In his method, you move a pattern piece a certain direction at each grade point. The grade points are related to those red lines but are actually located at a pattern edge, usually a corner or mid-point.

Anyway, the reason I didn't remember seeing those red lines is because I ignored them. As a CAD grader I simply select a point and enter in the amount of growth. In my head I know a piece is growing in the middle of the pattern even when I assign the growth to an outside corner or point.

Anyway, I have blathered too long.... The commenter is correct that with complex styles the growth/shrinkage must be placed properly. Handford illustrates a slightly more complex style of a bodice with midriff on pages 93-94. The pieces are taped together with strips of tagboard and graded at the same time. On page 89 Handford makes the suggestion of placing the style on a form to determine where growth/shrinkage should occur. While his suggestion is valid, it is difficult to make the conceptual leap from a 3D form with lines to a table top with flat pattern pieces.

I have never done this. Partly because I have only graded children's pattern pieces. There have only been a handful of styles that I would consider very complex. Since I did this on CAD I had the luxury of playing around with the grading until I felt it was correct. I came up with my own method that works for me. It is not much different from putting a jigsaw puzzle together and only involves a little bit of math.

CAD makes grading complex styles very easy. Unfortunately, the night is getting late and so a complete explanation will have to wait. For now, you must know your total width and length grades, say for a bodice pattern piece. If you have a bodice with a midriff and the total length grade is 1" (I don't know I am making this up...), divide the total length grade between the two pieces so that the growth looks proportionally correct.... Anyway, more later...