Liquid starch is an additive sprayed on clothes before ironing to make it easier to get crisp seams and a wrinkle-free finish. Commercial liquid starch is mixed with water in a spray bottle and misted onto clothes before ironing. The main ingredients are water and cornstarch, although some brands have additives including dyes, fragrances and soaps.
It is fairly easy to make liquid starch at home, and it can be much more cost effective for those people who use liquid starch on a regular basis. One tablespoon of cornstarch is dissolved in 1/4 cup of cold water and then added to 3 3/4 cups of boiling water. The mixture is allowed to cool and then is ready for use.