Final answer:
When preparing a spiral rod set, the hair must be completely dry or else the style will not set properly.
Step-by-step explanation:
When preparing a spiral rod set, the hair must be completely dry or else the style will not set properly. This is because wet hair doesn't hold curls or waves as well as dry hair. The water in wet hair causes the hydrogen bonds in the hair to break and reform, which can result in the style falling out.
A "spiral rod set" typically refers to a hairstyling technique used to create defined spiral curls or waves in the hair. It involves wrapping sections of hair around cylindrical rods, resulting in a spiral or corkscrew effect when the rods are removed. This method is commonly used to achieve a curly or wavy hairstyle without the need for heat styling tools like curling irons.