<html> At 07:20 PM 4/26/2005 -0500, you wrote: <blockquote type=cite class=cite cite><blockquote type=cite class=cite cite>Yeah, but usually the case is black...  And the ambient air is warmed by the light, too...  Maybe a white string cover?   --Cy Shuster--</blockquote> Space blanket - reflective Mylar. Ron N </blockquote> Yup. Space blankets are what I gave away at the class. They work great, but.... as mentioned, the ambient air will heat up anyway. Just as a little fill, here are some results from the research I did for the class I was asked to share in Nashville. The theme for the institute was "stability", and I've been wrestling stage lights and high-altitude sunlight for .... a looooong time. For the class, I filled up a steno pad with data and pestered a stage hand for days. I also monitored temps and pitch for a variety of performances, including full house w/symphony. (that was wild) I blanketed and cooked and probed and scratched my head...... a lot. Bottom line is, for me, I made the "performance" pitch a little more predictable. Just. I'm gonna skip the math and thermo 101 that put everyone to sleep in the class, okay? AND... these are condensed and are not intended to start any arguments. They are based on measured observations and physics. All the materials affected have different rates of heat transfer and expansion. Of the materials affected, the only ones that are significant on concert day are the strings, UNLESS the degree change is more than 15 degrees. Air movement is a factor, but the heat transfer rate is much faster for radiant heat. Most "significant" change happens in minutes, because the strings are the quickest to react. Space blankets (4 bucks and folds up into the size of your fist) work both ways. With the lid up, you can blanket the opening and allow for a slower ambient change, if conditions permit. With the lid down, if you blanket, you can "retain" the interior temp for an hour or so, depending on the venue. Blanketing or otherwise protecting the pin field is a GOOD thing. Most lights aren't as hot as you might think, but the only way to really know what's happening is to measure string temp often. Measuring plate temp is almost useless in the context of the few hours "around" concert time, UNLESS it's outside with snow or sunshine. What the plate does while reacting is quite different than what the strings are doing. Like I said, just a little fill for all the fine words of experience and wisdom that have joined this thread. Barbara, I'm glad you survived the class. I guess it wasn't the one where I forgot the heat lamp and     the facility ran out of hot water....... Thanks. %^) Later, Guy</html>