Attaching backboards to the tabletop

In the comments on making the backboard I was asked how I attach them to the wargaming table? With my recently made backboards I have been just propping them up again a book or piece of wood. This works fine as the foam board (from with they are made) is very light and sturdy. However, there is the disadvantage of reducing the tabletop space by a few inches. Not a bit issue, but there must be a better way which would return the lost tabletop space. 

Here is my approach for attaching a backboard....

First up using some wire. I cut a piece of wire and make a 90 degree bend (or thereabouts). Then I bend about 1 inch at each end to make two spikes.

The two spikes are pushed into the foam board base to create a wire loop that comes out at right angles

Using large paper clips the backboard is attached to the edge of the tabletop

The attachment takes up about half an inch of space

All neat and tidy with no hidden books or bits of wood holding up the backboard.