WiFi reflectors

This question is about the reflectors used for biquad antennas.

What are some of the materials used for reflectors? I heard that if you are in a crunch a cd can be used (CDs have foil backing that is supposed to be reflective). Is this correct?

I was wondering this because I am having a hard time sourcing cheap copper plates to use for my biquads.

My question to you guys is:

Can I use a piece of wood wrapped in the aluminum foil as a reflector without sacrificing the quality/performance of the part?

Also, cheap sources for reflectors would be appreciated if included with the response!

Thank you so much to everyone that took the time to read my post! Your responses are greatly appreciated!