Final answer:
You should apply a barrier film or neck strip to your neck before using a cape or hair cloth for hair-related services, ensuring the area is clean and free from oils or other substances that could hinder adhesion.
Step-by-step explanation:
Before applying a cape or hair cloth for hair styling or cutting, it is important to cleanse the area to remove any substances that could interfere with the adhesion of the cape to your clothing and skin. The surface must be free from oils, dust, or other materials. An example of the importance of a clean surface can be seen in the Take-Home Investigation where a sewing needle must be very clean in order to float on water because oils can alter the surface properties and prevent the needle from floating.
Similarly, the substance applied prior to a cape or hair cloth, likely a barrier film or neck strip, needs to adhere properly to your neck and should not be mixed with other substances which could lessen its effectiveness. Moreover, the concept of adhesion and how different substances interact with others is seen in fabric processing, where water doesn't adhere to waxy surfaces as efficiently as it does to bare ones. This understanding of adhesion also extends to how waterfowl are able to sit on water without getting their feathers wet, due to their feathers' special waterproofing properties.