Final answer:
Medium/large perm rods are used to give hair more volume and looser curls. They are typically used on long hair or to create soft, bouncy waves in shorter hair.
Step-by-step explanation:
Medium/large perm rods are used to create certain hairstyles by adding curls to the hair. The size of the curl or wave depends on the size of the perm rod. Larger rods will create bigger, looser curls, while smaller rods will create tighter curls. Therefore, medium/large perm rods are typically used when the desired outcome is softer, more voluminous and looser curls or waves as opposed to compact, tighter curls that you would get with smaller perm rods.
When styling, it's important to remember that the size and type of perm rod can significantly impact the final result. Therefore, it's important to choose the right perm rod size for the desired style. For instance, medium-large rods are generally suitable for those with long hair or for creating soft, bouncy waves in shorter hair.
Learn more about Medium/Large Perm Rods