Reddit reviews Hygloss Products, Inc. Magnetic Tape, Self- Adhesive, 1/2-Inch x 300-Inch
We found 2 Reddit comments about Hygloss Products, Inc. Magnetic Tape, Self- Adhesive, 1/2-Inch x 300-Inch. Here are the top ones, ranked by their Reddit score.
Self-adhesive magnet tape turns anything into a magnetCut to size300 inches per roll
http://www.amazon.com/dp/B0035YAVIY/
The sticky side hasn't proven to work all that well...
What about magnets? Stick a small one in the bottom of each hex and on the base, lay strips of magnetic tape on a sheet of MDF or foam core or whatever you want to use as a base. MDF might be better because you could use a router to make tracks for the magnetic tape so that the surface is flush.