there are two types of sparks if you will the low temp sparks like those that come from the carbonsteel/flint type of sparkmakers if i remember they are about 7-800 degrees, the other typpe is the ferro rod spark, which is much hotter like 1400 degrees. that is why you need the char cloth for the the steel/flint method. char clothe has a much lower kindling temperature than regular cotton, the char cloth is "coked" that is combusted in a low oxygen environment to leave a high carbon residual that has the lower kindling temperature than the original cloth from which it is made. it is needed to use the low temp sparking method.
alex
Yes, I understand that.
The thing is: If true flint and steel only works with a prepared tinder that you bring with you, that gives it a much narrower scope of utility for emergency wilderness survival, makes it much less useful. Though the sparks from true flint and steel are lower temperature, I expect that they can still also be used for found tinders, when done right, even if more difficult; and so I'm interested to learn more about this, to make flint and steel useful for anybody who has a knife, instead of just anybody who has a knife and charcloth.