Use sugar to wash and iron curtains in the washing machine.
As for curtains, they are usually washed at each change of season, both because they lose shine and for hygiene reasons. Curtains that are not washed regularly can cause allergies and irritation of the respiratory tract, as they accumulate many mites.
The good thing is that modern curtains can be washed in the washing machine without much damage. The secret is to soak the curtains with a tablespoon of detergent. Then put them in the washing machine and then add a tablespoon of granulated sugar to the fabric softener drawer. Sugar allows the curtains to regain their defined shape and consistency as soon as they are finished washing.
Obviously, you must not forget to exclude the centrifuge . Then you have to reassemble them just as they come out of the washing machine, so that they are left to dry, without wrinkles forming . The sugar will allow the curtains to regain their shape. Once dry they appear to have been ironed.