I have made my own from dry starch, per my Grandmother's instruction, for the "anti-flake" reasons as well but was THRILLED when I found Niagra Spray starch at WlaMar the other day with the "New: Will not flake on dark fabrics" version!
I have it and it really works!
I found the homemade kind should be made in batches you will use up within a week or so, or it gets really gummy. Perhaps the wrong recipe but, for a couple of bucks, I'm stickin with the new Niagra.