Reflectors for canopy?

[NucMed]

There are different reflectors out there and some claim to reflect more light than others which can be confusing when trying to decide which one to buy. Do the reflectors that claim to reflect more light do so because of how shiny or polished they are or is it because of how many bends they have? If it's due to how shiny or polished they are, can real mirrors be used as reflectors? I figured mirrors would be the best at reflecting light, right? Any thoughts? -Ryan