Setting up a big box for extra flies

A friend at work "rescued" a big (huge) box from the curbside trash
this week. He's a good guy, always finding good things curbside :-)

Anyway, this boxt looks like it was made for storing zillions of small
parts (it had a ton of tiny electrical parts still in it). He had no
use for it, and asked me if I could use something it for anything --
and instantly I thought that it might be perfect for storing the extra
flies that I tie. I"ll tie a dozen flies of each pattern when I'm on
a roll, and that means lots of extras need storing somewhere (usually
where my wife is not too pleased with). This could not only help me,
but I can see how my wife might be pleased if I could FINALLY organize
my flies and tying materials a bit better.

But I need to line the compartments with something to hold the flies
in place. I thought of buying sheets of Styrofoam or Velcro and
cutting them to size for each compartment. Or maybe cork, like from a
cork board material. Any ideas on this? What do you think would work
best?

Thanks in advance.

- Dave K.