Updated: Feb 6, 2019
Ensure you have all of your drafting tools to hand, including straight and curved rulers, tape, scissors, drafting paper and multi-colour pens (black, red and green recommended).
We are making use of the Mini Templates sheet to demonstrate how to work through the different examples to save paper and simplify what you are looking at. It is a good way to practice increasing/decreasing your drafts before you work on your actual patterns because mistakes can be timely.
You can access the Mini Templates from the Auxiliary Reference Downloads Documents page.
Pattern grading is when you take a draft and change it in all proportions to a different size. Manufacturers do this to a pattern generally to allow a pattern to be sold in multiple sizes. I pattern with different sizes shown can look more complex as you have multiple lines defining the edge of the pattern for each size.
This grading a pattern is a useful method to use if you have a requirement of grading one of your own patterns to a different size. However keep in mind that this is not likely to fit any other body but the body that the pattern was tailored for so I feel that the best use of pattern grading is to alter a pattern for yourself when you have lost or gained weight.
If like me your weight does fluctuate it can be frustrating after all the effort you have made with you patterns but with a little knowledge they can easily be edited up or down in size.
Whilst running my wellness clinic in the UK I realised that usually weight loss starts with the loss in weight and then shows up in inches the following week and continues along those lines and approximately one dress size is lost between 7lb – 10lb (or gained!) so a Base Template/Working Template and consequent Flexible Pattern is good for 10lb in either direction approximately. The difference between dress sizes is around 1” to 2” in the torso measurements for women but can be less for children as they are growing but this amount will differ from person to person as we all gain and loose in different body areas.
I would advise to grade up or down a draft 1 or 2 sizes only. Any more than this and you might find that the body shape has had some significant changes. So any more loss or gain than this and I would be tempted to start from the beginning and create a brand new Base Template and Working Template etc. This way you will get a chance to get a better fit all over and also hone your drafting technique and Test Garment construction to a perfect fit.
This Project will show you how to grade your draft up in size and down in size and you would grade any of your patterns in this way. You should be well on your way to getting the fit back into control doing it this way.
When you get to a point where you wish to grade your actual patterns it is recommended that you create a grading copy of all of the pattern pieces to preserve your original and work on the copy. This way if you do make any mistakes it is easier to back it out, whilst also keeping your old size pattern (just in case!).
When manufacturers create patterns they can have some very complex grading rules and you can read further into this subject if you wish to learn more. From the standpoint of simply reducing your patterns for a weight loss/gain then we can keep things very simple to get the pattern to a point where you can test it. Depending on the amount of grading you can apply some logic and define how you feel you should progress.
Check your measurements. Get out your previous measurement chart and check the measurements for your Bust, Waist, Hip Bone and Low Hip points (you could always grade a sleeve but as I recommend creating new sleeves anyway for any new pattern we are not going to look at sleeves here).
Decide by how much you are going to reduce the pattern by and where.
1 Dress Size
If you look at this example for just one dress size difference. There has been a 10lb weight loss for this client which has resulted in the following measurement changes.
You can see how the weight loss is not equally divided in inches as you go down the body. The decision is yours whether you take out the same amount all the way down the torso or whether you take out only what has been lost in inches at each defined area to get a better fit.
For just one dress size with these small amounts of changes you can get away with simply adding or removing small amounts off the Side Seam Line on both the Front and the Back drafts.
Looking at the Pattern Changes column simply divide each Difference by 4 (as you have 2 pattern pieces for the Front and one for the Back that are either cut separately to make a seam in the Centre or cut on the fold). You then simply take that amount off the side all the way down the Front and all the way down the Back. This is sufficient for amounts up to around ¼”.
This photo shows a Front and Back draft marked down the Side Seam in red reducing the drafts equally all the way down the side.
Obviously if you had differing amounts to reduce by as we can see with the client table above then you would mark each point for Bust, Waist, Hips etc. individually and then join the lines up to create the new shape in the side. So to confirm here you would remove ¼” off the Bust in the Front and Back draft, 1/8” at the Waist in both drafts etc. then redraw the Side Seam Line to join up the dots and create the new shape for the side.
2 Dress Sizes
However when we are dealing with more than one dress size in grading then we should consider a different technique.
Look at the following table where more weight has been lost and we are looking at reducing by around 2 dress sizes.
In this example if you simply removed the whole of the difference of the side seam Front and Back (i.e. Difference divided by 4 as we did for one dress size) you would start to impact the armhole size which would result in an incorrect fit and a requirement for an alteration. There would be no spread of weight across the body and if you think about it when you lose/gain weight you don’t just do it on the side of your body. So it makes sense to spread the difference across the garment.
We not only need to consider spreading the difference across the garment but also vertically down the body, if you think about it you are not flat and the bigger you get the longer the garment needs to be to cover everything up, the thinner you get the shorter your garment needs to be.
There are a number of key places on the draft where you can choose to remove/add space and your decision on placement of these Grading Lines will be affected by Dart position, Style Lines and Guide Lines and also other pattern design features such as Pleats and Tucks.