Places like Uline will have small boxes that are not a perfect fit for your tubes, and will happily make custom sized boxes. Prices and minimum orders are discouraging.
I make my own from cereal boxes. When really motivated I print the outsides, usually by printing the desired material on white paper and gluing that onto the cardboard with spray adhesive.
It is a bit tedious, but in a weekend you could have a tub of tubes boxed.