To each cup of water, add between one teaspoon and three teaspoons of cornstarch, depending on how stiff you’d like your spray starch to be. One teaspoon will give a very light starch, while three teaspoons is a heavy starch.
Starch Quilt Fabric / How to Make Homemade Liquid Starch
1 cup water 1 tbsp cornstarch Wisk cool water and cornstarch together in a saucepan until no lumps. Bring to a light boil until starch is desolved. Let cool then poor into spray bottle. Should last months without spoiling.