Originally Posted By: tanstaafl.
....

Let's see... I've got the router, the aluminum strip ... and about four feet of two-conductor wire to extend the power supply connector...
Aluminum is easy to form, but it is metal. If you have a suitable non-metallic material that would provide less possibility of messing with the WiFi radio propagation patterns.

Some plastics can be shaped and formed with mild localized heat such as a heat gun. Or find something plastic with a useable shape and cut pieces from it.