I was wondering what is a better reflector of light; a shiny silver material like Mylar, or a bright flat white paint?
i dun kno for sure but id have to say a shiny material..white still absorbs small amounts of light where as thats pure reflection...
smooth mylar is the best, but it's usually a pain in the ass to work with, clean, etc. i prefer flat white paint which should be 90% reflective. it's also easy to clean and restore to new condition.
mylar is best, your grow gets 30%+ of its yield off the reflection on your walls so you want to put the best in,budget permiting, but flat white will only give you 75-85% whereas mylar is 95%+.
While mylar gives better reflectivity, it needs to be completely smooth or it creates hot spots and it doesn't clean worth a darn. I like panda film (6mil) or flat white paint for its workability and cleanability.