I received a PDF pattern for the Tonic 2 t-shirt and since I still have not found an armscye-sleeve cap draft that I like, I wanted to try something from someone who presumably actually knows how to draft patterns.
I do enough taping PDF tiles together at work that I'm not excited to do it at home, but, hey, a free pattern is a free pattern and I already know that SBCC patterns mostly work for my body. I put on Father Brown and taped away. Then I used colored pencils to trace the small and medium cut lines in different colors to help distinguish the sizes. My measurements hit small, medium, and x-large, but I wanted to try to sew a straight large to see exactly how it fits before I went crazy with the alterations. When I was working on the MOH dress, I started with the alterations and ended up very close to the pattern as drafted. Didn't want to do extra work again, but I did know that I needed about 1.25 extra inches across the front hips and 5 inches across the back.
Because I needed 2.5 inches added to the back half width, I decided to add it in two sections. I figured the ease would be more evenly distributed that way. I also cut my lines all the way to the lengthen/shorten line (dotted line in the image below) because it seemed like the extra ease would fit more fluidly with a longer integration space.
In the image below, the orange line is the small cutting line, the blue is medium, the grey large, and the red my new large cutting line with the extra hip width added.
After I traced this, I thought it looked like I had simply added the extra space to the side. From what I've read, this will cause the garment to hand oddly because all the extra ease isn't evenly distributed.
Then I realized that I had kept the third with the center back fold cut-on-fold line straight when I spread the pieces. Well, that makes sense because otherwise, the center line would have a huge curve from the waist down and couldn't be cut on the fold.
I moved on to the front piece while I let that challenge ruminate.
In the image below the yellow is the pattern as drafted, the purple is where the pieces landed when I spread them to add extra space. The red is where I smoothed the lines or adjusted them to meet other lines. The green is the final hem cut-line.
The yellow is the pattern as drafted. The purple is where the pieces were after adding the extra width. The red is my new cutting line.
I started again with the back piece, this time adding half the extra space to the center back and half to the side seam. I realized I would need a back side seam because of how much extra space was added. I was quite proud of myself for remembering to add seam allowance.
In the image below, yellow is the pattern as drafted, purple is where the pieces landed when spread to add extra space, and red is my new cutting lines. The short grey line in the upper right hand corner is where the front side seam ended. I had to extend the back side seam about 1/8 inch beyond that in order to make the back hem straight like the original was drafted. This is why I won't sew for others - I'm more of a good-enough, make-it-work kind of sewer. At least in some aspects.
I let the pattern sit overnight because I know from experience that I probably missed something or didn't think of something obvious during the first go-around.
In all these alterations, I always start with the corner of the arm scye as a reference point. Especially in this case, where what I most want to see is how the original pattern fits me in the shoulders and sleeves, I didn't want to mess with anything in the upper torso. I did make a 3/4-inch swayback adjustment at the back shoulder, though.
As can be seen, my self-drafted pattern is quite different from the Tonic 2. This is where my lack of spatial intelligence shows through because I measured the original Tonic 2 pattern and measured my hips and added enough to have one inch of ease, about how much is in my self-drafted pattern. Yet there appears to be quite a bit more than that in the altered Tonic 2.
Maybe I did the math wrong somewhere. Instead of puzzling over something I am unlikely to find an answer to, I decided to eliminate the center back seam and see how things went. It looked like there would be plenty of room, so it was worth the risk.
In the image below, the red is the altered Tonic 2 cut lines and the purple is the original Tonic 2 cut-on-fold line.
This is what I mean about missing the obvious until too late. Even having made this alteration several times before, I still did the wrong thing. Maybe writing about it will make it stick in my brain and I'll be less likely to reverse directions again.