I like the spray starch too - I used the sizing for a while but it didn't seem to give it enough stiffness. And I also found when my spray starch scorched it was because the iron was too hot or my iron was dirty. So now I iron with a used dryer sheet on my ironing board and I spray the dryer sheet with water and run my iron over it between shirts or pieces of fabric. My favorite is also Faultless Professional - which is not always available. I have been known to buy the one at the Dollar Tree too. And like Onebyone - I will use it on the back of the fabric so it won't flake on the front.
I need to try some of the liquid starch someday but then I need to buy a special sprayer and not sure if it's worth it. I don't go thru is enough. Does it spoil?