Final answer:
After a soft-curl perm, a leave-in conditioner should be used to maintain the sheen of the hair.
Step-by-step explanation:
After a soft-curl perm, a leave-in conditioner should be used to maintain the sheen of the hair. Leave-in conditioners are designed to provide moisture, nourishment, and protection to the hair, making it softer, shinier, and more manageable.