Mylar is only more reflective because it's directionally reflective and that directionality makes it inferior to flat white paint for our uses. Figure out the angles in almost any grow situation and you'll see all that light is directed innefectively away from the plants.
There are tons of reasons why paint is better than mylar and I laid it all out in that recent myth busters thread if you want to check it out. Start at the last page.
I first started growing in the late 80's and never stopped learning all this time. Don't play me off like a fool. I'm not the one who needs to learn more about this subject.
No need to get defensive, i'm just stating the facts as I understand them. Do you have a link to the thread so I can see what you are talking about more clearly.
I hear what you are saying about directional reflection, but i'm not convinced that all the light is directed ineffectively away from the plants, as you have stated. I'd say that it would very much depend on the individual setup (lights, room dimensions, etc.). I also think that the fact that white paint absorbs 20% of all light that hits it must count against it's effectiveness, even though it diffuses the reflected light better than mylar.
I have used both paint and mylar over the years, and not noticed any real yield difference, to be honest (although i haven't exactly checked). I would be interested in a comparison of the two surfaces, with a light meter at various places in a grow room. Have you done anything like this?
I'm not questioning your knowledge on the subject, and will concede whatever point you like, if firm evidence is there to support it. I am not egotistical enough to think that I know it all, despite the fact I have been growing for a long time myself.
