Hello sewing friends! It’s Tamar from Tamar Hope Designs! We have been talking about pattern fitting lately! Last month we talked about adding or removing length. Today we will talk about blending sizes!!! This can get a little confusing, but it is so valuable as you try to make garments that fit perfectly.
Measure
The first step to getting the perfect fit is measuring! Make sure your measurements are accurate. Check out the tips in this blog post for measuring. I know it seems simple, but take the time to make sure you are measuring correctly. And take new measurements each time you sew! Those little kids can grow overnight!
Look at the Size Chart
Compare the measurements to the size chart.
Pick the size that is closest to your model’s measurements. If your measurements are between sizes, cut in between sizes. I know it doesn’t seem like a big difference, but every ¼” makes a difference in the fit. Pick the chest, waist, hips, and height size that are the closest to your model’s measurements. In the next step, we will blend between sizes. For example my daughter’s measurements are Chest 25”, Waist 22”, Hips 27”, Height 53.” So, if you look at the size chart she is a size 7 chest, 4 waist, 7 hips, 8/10 height.
Make some fit decisions
How do you want the garment to fit? Look at the ease. The ease tells you how loose the garment will fit. Olearia has a chest ease of .5 inches.
So, it is relatively fitted, but isn’t going to be tight. A negative ease creates a fit that is form fitting. An ease of 1 inch or more would be a more relaxed fit. For a dress with a .5 inch ease, you would probably want to grade for the waist to make sure that the bodice fits correctly. For a shirt with a .5 inch ease, you would want to grade for the waist if the waist size is bigger than the chest size. If the waist size is smaller than the chest size, you wouldn’t need to grade for the waist in a shirt. You would just need to be aware that not grading for the waist would create a looser fit, which is usually fine for a shirt. I normally would not have graded for the waist in this shirt, but I did grade for the waist here for the purposes of this tutorial.
Start cutting
As you cut, always be mindful of where that part of the pattern piece fits. The length (any horizontal lines in the pattern) will be cut on the height size. The width (any vertical lines in the pattern) will be cut on either the chest, waist, or hip size depending on where it fits.
If you have never blended sizes before, I highly suggest that you print out the pattern pieces and draw the lines on the pattern where you plan to cut. Once you have a little practice, you can blend sizes on the fly while using a projector. You could also use a washable marker to draw the lines on your fabric while using a projector.
I’ll begin with the center piece. The top and bottom are cut on the height size (between sizes 8 and 10). The sides are cut at the chest size (size 7). 
The pieces with armscyes get a little more complicated. Start at the shoulder and cut the shoulder and neckline at the height size (between 8 and 10 for me). 
Next, find the chest size (size 7 for me) and cut along the armscye on the chest size line.
Follow the chest size line down along the side. If you want to grade for the waist, use a ruler to draw a straight line from the chest size at the chest to the waist size at the waist.
If you need to blend to another size for the hips, draw a line from the waist size at the waist to the hip size at the hip. In this case, draw a curve to connect the three sizes.
At the hemline, cut across at the height size (between size 8 and 10 for me).
For the sleeves, you will cut the width the same size and the chest size, and the height the same size as the height size. (for me I cut on the size 7 width lines and drew a smooth line up to the 8/10 line for the height)
For the band, you will need to cut the height size. This one can be tricky, but if you think about it, your shoulders and neckline were all cut at the height size, so the band will need to match that.
Word of warning! I try not to blend to a size that is more than 2 sizes away from the chest size. For example, my daughter's waist is a size 4 and her chest is a size 7. I just blend from a 7 to a 5, not a 7 to a 4. More than 2 sizes can make the lines in the garment get a little wonky. If you need to blend sizes that are more than two sizes apart, definitely make a muslin to make sure the garment looks ok before using your nice fabric.
Sew
Try your garment on while you sew! You can always make the side seams a little smaller or a little bigger. Just make sure you also adjust the sleeve seam to match the side seam. You can also take a little bigger or smaller hem depending on how the length is looking. If you blended carefully, you shouldn’t have to make any adjustments as you sew, but it’s good to know that you can make adjustments as needed.
Learning to blend sizes is really a game changer! I hope this tutorial helps you get that perfect fit that you are looking for
Happy fitting!
-Tamar