Lesson 1
Thus he shewed me: and, behold, the Lord stood upon a wall made by a plumbline, with a plumbline in his hand.
Amos 7:7
Reading the Armscye Before You Touch the Sleeve
A plumbline does not argue. It hangs, and the wall is either true or it is not. Amos saw the Lord standing by one, and the picture is a comfort to anyone who works with their hands: there is such a thing as a straight standard, and holding your work up to it is not fussiness. It is honesty. Before any sleeve goes into any garment, hold the armhole up to the standard and find out what you actually have.
What the Armscye Is, and Why It Rules Everything
The armscye is the armhole seam — the curved opening in the body of the garment where the sleeve will live. Nearly every sleeve failure that gets blamed on "bad easing" is really an armscye problem. An armhole cut too small, or cut with the wrong curve, forces the sleeve cap to sit too high and puff, and no amount of careful pinning will talk it out of that. So the armhole is not the background of this work. It is the foundation.
Measure it along the seamline, not the cut edge. Stand a flexible tape on its edge and walk it around the stitching line of the front armhole and the back armhole, front notch to shoulder point to back notch and on down to the underarm. If your pattern gives seam allowances of five eighths of an inch, remember that the cut edge is longer than the seamline; measuring the cut edge will hand you a number that is too big and set you up for a sleeve that will not fit. Write the seamline number down. You will use it repeatedly.
Cap Height and What It Tells You
On the sleeve piece, cap height is the vertical distance from the highest point of the cap — the shoulder point — straight down to the level of the underarm seamline. In ordinary garments that measurement usually falls between four and six inches. In tailored garments, cap height commonly runs about twenty-six to thirty percent of the armscye seamline length.
That ratio is a sanity check you can perform in thirty seconds. Measure your armscye seamline. Take roughly a quarter of it. If the cap on your sleeve pattern is close to that, the two pieces are speaking the same language. A tall cap paired with a shallow armhole means a sleeve that will fight you. A short cap in a deep armhole gives a loose, casual hang with plenty of arm movement, which is exactly right for a work shirt and wrong for a fitted jacket.
The Shape of the Curve, Not Just the Length
Two armholes can measure the same and behave differently. Lay the front and back bodice pieces together at the shoulder seam and look at the curve as one continuous line. The front armhole is normally scooped a little deeper and hollower than the back, because the arm swings forward. The back is flatter and fuller across the shoulder blade. If both halves look identical, check your pattern pieces; you may have cut two fronts.
Run your finger along the curve. It should be smooth, with no flat spot or sudden corner where two drafting lines met. A corner in the armhole becomes a pucker in the finished sleeve every single time. Smooth it with a French curve while it is still paper, when correcting it costs nothing.
Handling the Cut Armhole
The armhole curve is largely bias, which means the raw edge will stretch simply from being carried around the room. Handle it as little as you can. Do not let a cut bodice hang off the edge of the table by its armhole. If you are working in a loosely woven fabric, a light row of stay stitching just inside the seamline, sewn from the underarm up toward the shoulder on each side, holds the shape without showing.
Keep the shears and the rotary cutter closed and set down whenever you leave the table, and keep the cutting mat back from the edge where a child could reach it. A sharp rotary blade is the fastest tool in the room and the least forgiving.
Before You Move On
Write three numbers on a slip of paper and pin it to the sleeve: armscye seamline length, sleeve cap seamline length, and cap height. Those three numbers are your plumbline for everything that follows. If they do not agree with each other, you fix the paper, not the fabric.
Check yourself
What is the armscye?
- The curved upper edge of the sleeve
- The armhole seam in the body of the garment
- The underarm seam of the sleeve
- The shoulder seam
Answer
B. The armhole seam in the body of the garment
Where should the armhole be measured?
- Along the seamline
- Along the cut edge
- Along the fold line
- Along the grain line arrow
Answer
A. Along the seamline
Cap height is measured from the shoulder point to which level?
- The wrist
- The elbow line
- The underarm seamline
- The hem edge
Answer
C. The underarm seamline
In tailored garments, cap height commonly runs what share of the armscye seamline length?
- About 5 to 10 percent
- About 50 to 60 percent
- About 70 percent
- About 26 to 30 percent
Answer
D. About 26 to 30 percent
What is the usual range for cap height in ordinary garments?
- Four to six inches
- One to two inches
- Eight to ten inches
- Twelve inches or more
Answer
A. Four to six inches
How do the front and back armhole curves normally compare?
- They are always identical
- The front is scooped deeper and hollower than the back
- The back is scooped deeper and hollower than the front
- Neither has any curve at all
Answer
B. The front is scooped deeper and hollower than the back
What does a flat spot or sudden corner in the armhole curve produce in the finished sleeve?
- A smoother hang
- Extra arm mobility
- A pucker
- A longer sleeve
Answer
C. A pucker
Why should the cut armhole edge be handled as little as possible?
- The dye rubs off
- It is largely bias and will stretch
- It shrinks when touched
- The seam allowance dissolves
Answer
B. It is largely bias and will stretch
What does the Amos 7:7 picture of the plumbline suggest about handwork?
- Measuring is unnecessary fussiness
- Only builders need a standard
- Walls are more important than garments
- There is a true standard, and checking work against it is honest
Answer
D. There is a true standard, and checking work against it is honest
Which three numbers should be recorded before setting a sleeve?
- Thread weight, needle size, and bobbin count
- Fabric width, price, and fiber
- Armscye seamline length, sleeve cap seamline length, and cap height
- Hem depth, cuff width, and buttonhole size
Answer
C. Armscye seamline length, sleeve cap seamline length, and cap height