Monday, October 29, 2007

Light and Color Question

Ok, I'll admit it...I'm stalling.

I got MY Weekender finished, and now I have to turn around and do another one...a Christmas present...before I change the thread in the serger.

And I decided that I really, really should add some interfacing to AT LEAST the straps of the next one. My straps feel a little flimsy. It probably wouldn't hurt to interface the bag facings, either. Or the bottom.

More cutting...tedious cutting at that.

So I'm Not Real Enthusiastic about the next up item...but it must be done, that's Christmas.

Maybe I should just put on a recording of 'We Are Santa's Elves' and sing along whilst I make it?

Anyway, I've got a question for everyone...

Last night was our quarterly Night of Worship at church. It's an awesome service...two hours of singing and praying. No preaching, just worship.

But the choir was instructed to wear jeans with black shirts. And something interesting happened with the lighting. Every time the lighting guy hit the choir with just blue lights all our black shirts turned deep red! I had on a black microfiber charmeuse blouse (Silhouette Pattern's Pam's Blouse, if you're interested) that turned the most GORGEOUS shade of burgundy...I'd buy fabric that color in a heartbeat. To complicate matters, it was interesting to note that my black leather jacket that I wore during rehearsal before the service (it was chilly in the empty sanctuary) stayed black no matter what color of light was on it.

We had no good consensus on why the fabric changed color, let alone why the fabric did and the jacket didn't, and My Sweet Baboo joked that I'd probably blog about it to find out.

Why not?

Anybody know why blue light turns black fabric red?

I have a theory, but I'm going to wait and see if anyone posts a definitive answer before I post it. I don't want to appear to be a doofus. (Maybe it's too late for that?)


  1. Let's see if I remember this from lighting class...
    the blue light will cancel out all the blue dye that is in the garments. That leaves what remains, which is the red and brown (making burgundy).
    In years past, if you were to appear on a television program, you would be encouraged NOT to wear blue, because the blue would be cancelled out by the lighting. I'm pretty sure technology has advanced to the point where this is no longer as much of a problem.
    Black dye for garments is not pure black. It is a conglomerate of colors, added to dark blue. Leather dye is probably closer to a true black.

  2. Oh, Shannon, I figured you'd have an explanation!

    I based my theory on a Peter Whimsey story I read in which the murder's alibi was undone by the fact that a red dress looks white under red light...that is, that a colored light washes out its own color, and so I thought that the blue was being washed out of the black.

    However, since black is supposed to absorb light, someone (who will remain nameless, but I bet you can figure out who it was) scoffed at my theory.

    The trick is that black fabric dye isn't true black!! That's the answer I needed!

    So now I get to say, "I told you so..." ;)


  3. Hm...on second thought, I guess we were both right. The fabric wasn't really black, so the light washed out the blue in the shirts; the jacket was really black, so the light had no effect on it.

  4. Yup! What you and Shannon said!
    I still get confused about how and why the color of the light will affect the color of the fabric on stage. I learned it all, but it hasn't stuck. I'm a pigment kind of thinker I guess.
    And also, that's why it's really, really hard to dye fabric a pure true black. There's so often a strong tone of red or purple that comes through.