When you say flint do you mean like a firesteel ferro rod, or flint like the Indians used on arrows? If you need to depend on matches or flint to start fires. Then now is the time to practice and learn new ways or skills. The fresnel lens is a great way to make fire, but believe it or not it takes practice to be successful. Most people think you just concentrate the beam on a leaf and it will burst into flame. For the most part that is not true, use the fresnel lens to get a coal then by blowing on the coal and dropping it into a tinder bundle you get fire. Punkwood or tree fungus= tinder fungus is great material for catching a ember from a fresnel lens. One other method I use that no one else does is toy caps and a gator clip. Seed or cattail fluff, cotton and jute will catch the fire from a toy cap. This is now my most used way to start my campfires.I have a large number of matches put away in my emergency supplies, as well as several flints. However, it just occurred to me that if anything happens to the matches and flints, I'm not certain I could get a fire started. Is there anything besides the friction of rubbing two sticks together? And does that really work anyway?