"Six months to Ninety" - Darts are essential in patternmaking!

Six Months to Ninety - A Dress Pattern Book by Joyce G. Morgan, Whitcombe and Tombs Limited, Christchurch, 1964

I found this in a second-hand bookstore in Auckland,  New Zealand. I am learning so much on how to make dress patterns from this book! 

It explains how and why patterns are shaped- to fit flat paper to the various contours of the body. 

The "Brush off those frills" dress uses an elastic waist for an hourglass silhouette. But after reading this book, I've learnt that properly tailored dresses need darts, usually under the boobs, in the back, and on the waist and butt. 

Here is a quick summary to its introduction on darts:

(Darts are small triangles cut on a side of a pattern. After the fabric is cut according to the pattern, the dart is sewn closed to create a curve in the fabric. This curve allows for the material to follow curves in the body, e.g. waists, boobs and butts. So darts allow for a dress pattern to perfectly fit to the shape of the human body.)

• For a pattern to fit the body properly it must have darts.
• Wide darts for large curves and smaller darts for where curves are less prominent.
• The only necessary curve that must be marked out by a dart is the underarm. 
• All other curves can be fitted with either tucks or gathers.