So Fine Aerosol Hairspray is designed to enable anyone with fine or thinning hair to achieve fantastic updos, and hold fine, fragile hair in place. (Firm Hold) Want to hot iron or hot roller hair? SO FINE HAIR AEROSOL SPRAY can be used as a non-stick setting lotion, and also as a finishing spray after you have styled your hair. Updos on thinning or fine hair hold beautifully. It gives a hold of approximately 8 on a scale of 1 to 10. So Fine Hairspray is humidity-resistant and will hold true in high-humidity conditions. It can be used with a curling iron to create beautiful curls or a flat iron to create straight hair.