A shirt pattern, drafted to your measurements

Nape to the waist reference, down the centre back. Sets the back block's overall length.

The front's counterpart to full length back. Front and back are aligned at the chest line, not the hem.

Measured up the centre back. The difference from full length back places the back neck point.

Places the centre-front neck point, which sits deeper than the back's — the front scoop.

Sets the vertical guideline the back shoulder slope lands on.

The front's shoulder guideline. Armstrong adds 1/2" to it when drafting.

A diagonal from the waist to the shoulder tip. Longer = a flatter shoulder.

The front diagonal. It is legitimately longer than the back's — that's why the raw armhole runs front-heavy, which the yoke then rebalances.

Positions the back armhole's inner guide. Armstrong adds 1/2".

Positions the front armhole's inner guide. Armstrong adds 1/4".

Neck point to shoulder tip. Drafted with 1/2" added; back and front are equal by construction, so the shoulder seams always match.

Sets the neck-shoulder point. The collar is DERIVED from the drafted neckline, never measured directly.

One quarter of the chest. Defaults to chest ÷ 4; front and back shaping comes from the draft's own ease constants, not from unequal quarters.

The front quarter. Kept independent so a personally-measured unequal split can override the default.

The draft takes 2½" off for the cuff to find the wrist line.

The sleeve cap's height. This is what the auto-fit below adjusts to bring cap ease into range.

Sets the biceps line width — half each side of the grainline, so the full width equals this.

Cuff length is this plus a 1" button extension. Standard: S 9", M 9½", L 10".