Help me find this COE 82 amber powder!

[Alexis Dinno]

About 10 years ago I purchased 250g of amber powder from C & R Loo. This color turned out to be reactive due to silver in the formulation, and it produced amazing optical effects. In fact, these were dichroic effects, where the reflected colors (viewed through the opposite side of transparent glass) varied in piece to piece from robin's egg blue through teals to a light alligator green, but the transmitted color was amber brown, as how in the same piece below viewed in reflected light on the left, and transmitted light on the right (I am guessing the bluish/greenish is due to a diffraction grating produced by the spread of silver ions near the interface of the clear glass substrate—in effect doing what happens in human blue or green irises, western scrubb jay feathers, etc.):



The silver in the amber also bled out and stained the surrounding glass yellow, as you can (kind of) see in the below detail:



This stuff was rad, so I ordered another 1kg of it. That ran out, and I ordered another... which turned out to be a completely non-reactive amber brown (even though all three shipments bore the same "FF0-80-0" catalog number—edit: actually on rechecking the labels they were "FF0-80-0BJ," "FF0-80-0," and "FF0-80-0"). Other than identifying the current source of the powder as Optul, folks at C & R Loo were all "No idea what you are talking about!"

Anyone know where I might find the float-compatible silver-bearing reactive amber powder?

[Kevin Midgley]

effectively you have a silver stain which may be difficult to track down these days.
If you have not used stain before and it looks like you did with those pieces, it is advisable to fire face down or risk have stain fumes reappearing on your glass work at the least opportune later time.

[Alexis Dinno]

effectively you have a silver stain which may be difficult to track down these days.
If you have not used stain before and it looks like you did with those pieces, it is advisable to fire face down or risk have stain fumes reappearing on your glass work at the least opportune later time.

Thank you for the response, Kevin. I am familiar with the perils of working with, for example, silver inclusions in the kiln, but I wonder if you can help educate me a little more?

I suspect you are using the word "stain" in a technical fashion, and I am not familiar with "stains" as used in the glass world. Where can I learn more about them? Relatedly, do you understand silver stains to produce the kind of dichroic effect I wrote about in my first post?

Finally, indeed the powder was fused between plate glass and the kiln shelf (which had a layer of thin fire atop it, in addition to kiln wash) for these type of pieces, however (unlike in the example above) I subsequently added a lip-wrap which entailed re-fusing the pieces with the amber side up. I have not noticed any untoward effects of silver on other colors, clear glass, etc. upon firings subsequent to the amber firings. My thought is that the silver is integrated in the glass at the point of the second firing, and will not present much in the way of pollution for future firings. Thoughts?

Very best,
Alexis

[Kevin Midgley]

The instructions were clear when I learned. Stains down on a thin bed of throw away whiting and paints up.
Silver in my experience can come back to haunt you months and months after the fact. Your first comment on seeing its golden return will be a 'what the..." Where did that come from? The answer it escaped during an earlier firing and has returned at the least desirable time and location. In my case 6 months later after multiple per day daily firings of the kiln it destroyed a piece.
When you pick up a stained piece of glass off a bed of whiting you can see the stain trying to escape into the kiln from the whiting turning golden wherever the fumes reached.
Depending on how stains are fired and the nature of the stain itself, it is possible for it to 'metalize' which in most cases is not desirable.
So first you are going to have to track some down somewhere and then experiment with whatever stain you manage to get your hands on. There are different colours.
I'd suggest looking in England for it. The companies making it have changed ownership so many times I don't know who is now.
Private Message Don Burt as he might know. ALL his posts are also worth looking for.

If you want to go down the rabbit hole of learning Albinus Elskus the Art of Painting on Glass, out of print is a good one.
The price for a new copy $1400 but used ones are from $70 here as of this date https://www.abebooks.com/servlet/BookDe ... ults-_-BDP

Another one is here: https://www.abebooks.com/9780823055258/ ... -1-_-image That you can actually find one of these for sale is remarkable. They get stolen from libraries.

And these guys are good. https://www.abebooks.com/products/isbn/ ... g=pd_b_p_1
They have all sorts of online lessons but buy their book.

[Alexis Dinno]

The instructions were clear when I learned. Stains down on a thin bed of throw away whiting and paints up.

Thank you so much for the reply, Kevin, but I am still at a loss to understand what do you mean by a stain?

(I have been writing about powder, i.e. glass frit that has been crushed to a very fine—powdery—grain size. Not sure that is what you mean by stain?)

[Lynn Perry]

Alexis, perhaps this is the explanation of staining you are seeking.

https://boppardconservationproject.word ... ver-stain/

You may have to cut and paste the link.

[Alexis Dinno]

Alexis, perhaps this is the explanation of staining you are seeking.

https://boppardconservationproject.word ... ver-stain/

You may have to cut and paste the link.

Thank you, Lynn, that educates me about stain.

But I think stain is more or less unrelated to my original question.

[Alexis Dinno]

At last I have an answer all thanks due to Skyglass (via a private communication): Optul COE 82 Topaz is reported (with a beautiful photograph) to produce the kinds of dichroic effects shown in my pictures above. WOOT!

These colors depend on heatwork, and range from violets at the more minimal ends of heatwork to robin's egg blues, teals, and alligator greens.

HUZZAH! Calloo! Callay! &C.

[Kevin Midgley]

Finally an area to explore to try and create glass like Brian Blanthorn created.
His techniques were most certainly not simple.
Now, when do I find the time?