http://www.shopbrodart.com/library-supplies/archival-supplies/archival-storage-boxes/Archival-Specialty-Storage-Boxes/_/Post-Card-Boxes/

N.B. presuming the 4 1/8" H dimension is even the outer dimension, this means that one can't easily keep tab cut dividers which often go from 4 3/8" to 4 1/2" tall in these boxes with the lids on properly.

Instead, one may prefer their slightly larger microfiche boxes which go up to 4 3/4" which should also presumably fit their microfiche divider guides for sectioning one's work.

Another subtle difference in these two boxes is that the smaller is 60-pt paper versus 40-pt for the larger microfiche box, which means that while sturdy, isn't quite as sturdy.

http://www.shopbrodart.com/library-supplies/archival-supplies/archival-storage-boxes/Archival-Media-Storage-Boxes/_/Microfiche-Storage-Boxes/

These should easily fit 4 x 6" index cards as well as card dividers with taller tabs which commercially don't often get taller than 4 1/2".

See also microfiche divider guides.

reply to GnauticalGnorman

Don't frown at cardboard. Everyone starts their journey with a single card and a humble box. Filling up a first box is an accomplishment that gives you time to dream about the box you want to have.

Of potential interest, the cost of index cards to fill these files will be almost the investment in the box itself. Is this similar to the rule of thumb in the art world that the price of the frame should reflect the investment in the artwork?

This video includes Alex Faaborg on Tedx Talks sharing how VR virtual reality can positively impact education. The introduction of google cardboard is reviewed along with design techniques.