Tartan; A tip I learned from heirloom sewing that I have found very useful is: Soak the affected area in a bowl of water and add in a couple of denture tablets. Let it soak for several hours or overnite and voila` the scorched area is magically gone!
Now, since heirloom sewing involves alot of starching it may be the starch doesn't let the scorch marks go too deep which may be why soaking with denture tabs works so well. I haven't used it on a plain fabric scorch but it might be worth trying next time.
Just my 2 cents worth. :)