Spray starch is a fabric treatment used to stiffen and smooth clothing, making it easier to iron and giving garments a crisp appearance. It is typically available in an aerosol can, allowing for easy application directly onto fabric surfaces. When applied, spray starch creates a thin film that helps to hold the shape of the fabric, reducing wrinkles and enhancing the overall look. It is commonly used on items like shirts, tablecloths, and curtains, and can be found in various formulations, including those that are scented or contain additional fabric care properties.