Silver film vs. White paint

>You might find that just using a white material will work as well as a
>metallic one.   White paint gives virtually the same amount (%) of
>reflectivity as a mirror.  
>Pete Mohan

Reflectors     Approximate Light Level

White paint (old)   100%

White paint (new)   105-120%

Anodized aluminum   110-140%

Silver film   120-150%

Enhanced aluminum   120-150%

40W CW
All ballast factors are 0.94.
Optical system or reflector modifications may change illumination uniformity.
Source for table: Advanced Lighting Guidelines and manufacturer test data.