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.
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...