The following diagrams from a 1950s high school home economics textbook illustrate how you should pin the curls to achieve the desired side effects, from close to the head to fluffy fullness!
Note the direction of each row of curls. Also note the reference to the stem of the curl. There are three parts to a pin curl: base, stem, and circle. The base is the stationary part, attached to the scalp. The stem is the section of hair between the base and the first arc of the circle, giving the hair its direction and movement. The circle is, of course, the part that forms a full circle. The size of the circle determines the width of the resulting wave and its strength. Here are some guidelines:
- Start with clean, wet hair.
- Divide the sections of hair for each curl as equally as possible.
- Each circle should be flat and smooth on its base.
- The direction in which a curl and stem is placed determines the finished style.
And just fyi, I don't claim to be an expert on pin curls. I simply lived through 1950s and 1960s when their use was the mode of the day. As a small girl, my mother would curl my hair with rags (whole different topic!), then as I got older, with bobby pins to create pin curls. And by the time I was in high school, curlers were all the rage! ;)