I don't use the canned starch, it's expensive and doesn't go far, I use Sta-Flo concentrated and dilute 50/50. A lot of people spray the starch, then iron, but complain because the gunk gets all over their iron and flakes on the fabric, this is because they're ironing the starch and not the fabric. After spraying, the fabric needs to have a minimum of 2 hours to absorb the starch, so after starching, put the fabric in a large ziplock bag or the like for a couple hours, take it out, shake and either air dry or put in the dryer for a few minutes, then iron, I will usually spray with water while ironing, but I've never had any gunk or flakes from doing it this way.