YOu don't want them bouncing around. The edges can chip off just striking each other. Put them somewhere stable, and well padded. Make a flint wallet to carry a few in your range bag, or hunting bag, when you need to change a flint. Unless you are going trekking for a year or two, a couple of extra flints is all you will usually need for a day at the range, or a week in the field. They are brittle, like glass, but much tougher. You don't want to be hitting them with a sledge hammer, or any other heavy dead weight. They can break. Considering how much they cost, take care of them. I bought 500 20 years ago, and sold a few hundred to other members of the club. I kept 100 for myself, and am down to about 25 now, with a few culls I can save with a diamond wheel to flatten some humps on them. Some were too small to be useful in anything but a pistol lock. Some are too thin to give much working life. I will be due to buy some more next year, or the year after, I think. I am getting 80+ strikes per flint with these Tom Fuller flints, and I would like to buy more.
If I were going to store a quantity of flints today, I would lay them out in layers in a box, like candy in a candy box, with cloth or paper towels between the layers, or even cardboard, if I could find the correct size. If I could find some kind of cheap tray that had compartment wide and long enough to hold one flint per compartment, and then layer them in a box, I would do that. You might check the Hobby stores, and see what they have that might work. The little buggers are so expensive that I would hate to open my box up and find one of the edges chipped.
