When finished with an empty cardboard salt container, cut the whole round top piece off and measure to fit a canning jar ring. Trace and cut with the flat part with scissors to fit a pint canning jar.
Don't throw that empty salt container away. You can remove the top with the spout and cut it down to fit inside a mason jar ring! Now you can put all kind of things in the jar and easily pour out the amount you want.
Don't throw that empty salt container away.