Why modal needs a little more attention
Modal is a semi-synthetic fabric. It is stronger than silk but more delicate than cotton. Heat is its main enemy. Hot water relaxes the fibres and can cause shrinkage or loss of softness over time. The good news is that caring for it properly takes almost no extra effort once you know what to do.
Machine washing
Use a delicate or gentle cycle at 30 degrees or below. Put the hijab inside a mesh laundry bag if you have one. This protects it from friction against other garments. Use a gentle detergent without bleach. Fabric softener is not necessary and can sometimes coat the fibres in a way that changes the drape.
Hand washing
Fill a basin with cool water and a small amount of gentle detergent. Submerge the hijab and move it gently through the water for a minute or two. Do not scrub or wring. Rinse thoroughly in cool water until no soap remains.
Drying
Do not tumble dry. The heat damages the fibres and can cause permanent changes in the texture. Remove from the wash, gently squeeze excess water out without wringing, and either lay flat on a clean towel or hang on a hanger away from direct sunlight. Reshape the fabric while it is damp so it dries in the right form.
Ironing
If you need to press your modal hijab, use a cool iron on the reverse side. A cool steam iron works well. Never iron on high heat. If you are unsure, use a pressing cloth between the iron and the fabric.
Storage
Fold loosely or roll rather than compressing tightly. Store away from direct sunlight, which can fade colours over time. A breathable fabric bag or drawer is ideal.