I am not entirely sure where this picture came from.
I suspect it is from Anthropologie. It seems to be kicking about pinterest mostly, and seems to be quite old as it's lost it's links. But I saw it, and I liked it.
Here is my version:
Here's how to do it. I suppose in internet speak, this is a 'DIY Anthro Knock Off'. This spans over 3 posts because I'm trying to not turn every post into a thesis.
Stretch/Jersey with a horizontal stripe.
A T-shirt pattern which you know fits well.
Chalk / rulers
The usual sewing supplies.
Just so you know, I drafted this based on the same pattern I made this basic, bog standard t-shirt with.
It does fit well. Mine has a dart at the bust, but it wouldn't be necessary to have a dart. If you would like to see how to copy an existing t-shirt to make a pattern, check out this post.
I have the pattern marked with horizontal lines to indicate the bust, under bust and waistlines.
To create the pattern, we have 4 pieces to make.
The back and sleeves are exactly as for the usual t-shirt. So I can cut them straight off the original pattern.
The front has two layers - which I will refer to as the front and the knot layer.
To make the front layer, I need to create that central gather. Working on two layers to make both sides, I do that by marking parallel lines at the edge of the fabric 15cm - 20cm [6-8"] apart. (I did 15cm, as the fabric was fairly stiff but could easily have gone for 20cm.) Place the pattern piece to one side. like this: (The stripes in the fabric should be horizontal to the pattern piece)
I've done a sketch as it's much easier to see than in the photograph. Parallel lines are 15-20cm apart.
Draw a vertical line in chalk, up from this point.
Measure the stitching line on the back neck:
On this photo the top cut is crooked, as I was considering tapering it, but I straightened it up later.
I mark on the fabric a point where a V neckline would finish, and I also mark a line halfway between the fullness of the bust and the underbust. Diagram here as the chalk just did not show up in the photo.
The knot is essentially composed of 2 trapeziums (or trapezoids depending on your location) which are intertwined.
To make these trapeziums, we need to measure on the front pattern piece.
The seam and knot will sit between the bust line, and the underbust line.
To find the shorter edge of the trapezium, I measure across this line and back, with an extra 2.5cm [1"] loop to make the knot, like so:
And for the longer edge I measure like this:
The top of the tape measure goes right into the armscye, so that it is directly above the bottom edge. It cuts through the edge about 5cm from the bottom of the armscye.
That length is the longer side of the trapezium.
To find the height of the trapezium, I need to measure here, as this is the widest part.
With those measurements in mind, I cut two shapes like this:
Each one will fold inwards like so:
But for now, that's all the pieces cut. Next up, construction.