Thursday, December 17, 2009

Your Glass is Crass

Seasonal activities have kept me busy as a one fingered feather plucker before Thanksgiving, so I've been a bit lax in recanting the rest of the Italy trip. I'm about to start a few art projects now though and am faced with a dilemna. Maybe some of you can help me out with it.

The subject which I'm doing a mosaic of has very intense purples (violet cobalt manganese oxide pigments), but the only commercially available glass I can find with the color intensity of the object I'm trying to represent would be cobalt blue. So I've been hitting the color theory books and websites, trying to figure out placement or backgrounds that would make intense cobalt blue seem more like a shade of rich purple in context.

Here is an example Roman model boat of a cobalt blue glass in the British Museum from the first century. It's blue, but kind of purple as that glass often is. I like to think that 1900 years ago, someone served gravy from this.

While wading through all of the color theory information, I've come across some examples of how the human mind processes color and shape. Some of these examples involve motion, but many are just how the colors and shapes are processed.

For example, check out lilac chaser on Michael Bach's site.
This guy has collected several other visual phenomenon examples that are fascinating to me.

I'm leaning towards giving the cobalt blue a background of its inverse color in green. Given an unsaturated background of green, because of the way eyes process color with their red and green cones and rods, it should trick the mind into attributing more saturated red in the object done in cobalt blue (which is what I want, to play up the violet elements of the cobalt blue).
What do you guys think?

Another thing that I discovered while pouring over glass chemistry was a complete surprise. Back in the 20th century, they used to make glass with uranium dioxide in it (completely radioactive). This sounds like a horrible cancer causing express train to legal liability, right? Well it turns out that glass is a great radiation shield, so this radioactive glass is not the deadly killer I first suspected it might be.

Shining an ultraviolet light (as above) on glass made like this causes it to flouresce in a manner that even Monty Burns would be proud of. I've now taken to carrying an ultraviolet light with me everywhere to check for *ahem* flourescence.


  1. That is really interesting - reminds me a bit of the lead in Fiesta Ware, for some reason (though it probably is not really a good comparison!)

  2. mm hmmm...or are you checking sheets for specimen? It's Friday, and everytime I read the word "glass" in your post, I couldn't comprehend why it didn't end with the word "of wine". But then I got to the radioactive glass I was mezmorized.

    No help in the cobalt vs. purple department, but did you know that everyone is colorblind in their peripheral vision? You can see an object, but unless you knew the color beforehand, you can't identify it when using your peripheral vision.

  3. I like visual trickery! That lilac chaser thing is cool!

    I do sort of the opposite of what you're after with eyeshadow, I use purple (or pink or copper-brown) shades to make my hazel eyes look more green - and never wear green shadow, which makes them look brown!

    I think you're on the right track, if you're concerned to get it perfect maybe do some experiments with colored paper? or small bits of cheap glass?

  4. In class we did something like the lilac chaser, we just painted a purple spot, stared at it, the looked at the white canvas and it looked yellow.

    Though, one thought I had was could you use stained glass to make the mosaic tiles? I would think that spectrum would have a purple that you like.

    Otherwise a red/brown background could help, and maybe if there is gold or yellow tiles around it?



  7. I would like to help out, but I'm a total glass klutz. I like the cobalt blue glass boat, though. Yeah, I know... I'm such a great help.

  8. I would hate to consider all of the other places your light would detect, ahem, flourescence. Keep it out of Vegas or you will likely hurt your eyes.

  9. MERRY CHRISTMAS! ^_________^

  10. Hmm...I think I'll use that as my excuse too. "I'm just checking out the glass..."

    I love anything blue. Makes my eyes look awesome.

    Of course I'm going to come to your blog and comment about myself on your lovely post. It's how I roll.

  11. Lidian,
    Did they just paint the lead on the Fiestaware? Sometimes I wonder if we overreact to things like the small amount of lead paint in plastic items from China. Compared to putting it in plates, it can't be that bad.
    I want to get some uranium glass now...

    Haha, yes glass of wine. I had several of those this weekend, including one out in the spa when it was about 40f outside.
    I didn't know that about peripheral vision, I'll have to do some experiments.

    Did you see some of the other ones that guy had dug up? Thanks, I am actually experimenting with loose glass tesserae, it seems to support the hypothesis.

    I did look for some 'regular' stained glass instead of smalti. The one you linked to below was something I was considering as a possibility. I do like how the cobalt blue is so saturated and seems to almost glow with the rich indigo. It's a shame I can't find glass so luminent as that.
    I do have some tile that is the right 'hue', just not bright/saturated enough.

    Dutch Donut Girl,
    King Tutankamon had a headrest made out of cobalt blue glass. When I saw it earlier this year, I thought it was weird that they had such technology so long ago.

    Yes, I don't want to think about it because I go there sometimes when I want to win some money at single deck blackjack.

    Ragazza Anna,
    Spero tu stia bene e il nuovo anno è meglio. Ancora godendo la lavastoviglie dei vostri?

    I guess you have green eyes then? It's ok, you can make it about yourself, especially if you talk about #7.

  12. Careful where you shine that light. You could embarass either yourself or someone else quite easily.

  13. You're a one fingered feather fucImeanpluckwhatthewhat?

  14. The Jules,
    I always just tell people it was a Highlighter (tm) accident.


    So no one got my 'pouring over glass' pun? Beh.

  15. Well, I can't help you with color cause apparently I don't know anything about it anymore.

    The history on that little boat was real cool.

    The Lilac Chaser was amazing, but reminded me I know nothing about color.

  16. Brown, actually. And aren't you the pervert!

  17. Heather,
    I'm still learning about color.
    Lilac Chaser was pretty wild, huh?
    I like old stuff.

    Brown, eh? Well you know what they say about girls with brown eyes, right?
    Yes, I never said I'm not entralled by #7.