What Different types and strengths of perm lotion available and when they should be used for best effect?

There are generally three types of perm lotions: alkaline, acid, and exothermic. Alkaline perms are stronger and suitable for coarse or resistant hair, as they create tighter curls. Acid perms are gentler, making them ideal for fine or damaged hair, resulting in softer, looser curls. Exothermic perms generate heat during the process, enhancing the curling effect and are versatile for various hair types, offering a balance between strength and gentleness.