Things to take note of before calculation

When subtracting 1.5" from the bust measurement and the answer comes out as 34" or less the blouse pattern to be made is size SMALL. If the answer is 34 or 36" then the blouse pattern to be made is size LARGE.
A ragal line is the name used for the lines drawn horizontally and vertically when beginning to create the pattern.This will be illustrated later in the diagram.The vertical line indicates the height of the ragal line.
The height of the ragal line is measured differently for small and large sizes.For small sizes the ragal line height would be the bust measurement divided by 4.For lager sizes it would be the shoulder to shoulder measurement divide by 2.