Topic: Another Schmetterling question for Pamela

[Frank]

Small scale makes sense though, the technology is cheap now but must have been expensive in the early days. If they got an order for say 50 or so pieces in a particular colour it might not have proved worth making a colour batch even if it was a listed colour. (Speculation)

http://www.valspar.com/val/packaging/glassCoatings.jsp

[Frank]

This site gives some history and reasons for use. Note that it only applies to more recent developements, circa 20 years.

http://www.cwc.org/gl_bp/gbp3-0105.htm

An important difference in this newer technology is that they have strength without firing. But apart from the reasons given above, another one that uses a hot coating process says:

Our Certincoat and Tegoglas products improve the strength of billions of bottles and glass containers manufactured around the world each year. The Certincoat System deposits a uniform tin oxide coating on every type of glass packaging, while Tegoglas coatings improve the lubricity and scratch resistance of the container. Together, our products reduce bottle weight, improve strength, and enable faster filling speeds and increased output.

These are obviously not directly relevant here but the justifications in terms of cost reasoning would have applied with fired on coatings too. I will not add anymore to this thread about this more modern coating as there is no relevance. I shall see what I can dig up in my books on earlier processes.

[Leni]

Has anyone else got an example of Walther glass with an applied colour coating?

Well, this swan vase isn't Walther, but I believe it's Mikasa, which is a 'descendant' of Walther, isn't it?  http://glassgallery.yobunny.org.uk/displayimage.php?pos=-2261

I think the pink colour is an added coating   :shock:  :?

[Glen]

Leni, yes, absolutely. I think the contemporary "Walther" items are decorated in several colours too - I've seen rose and green tints added. It's the earlier ones that puzzle me.

Glen

[Glen]

It may be worth adding these facts into the puzzle. In the Walther 1936 catalogue, "Sonnenfisch" was made in rose, green and blue. Clear (white) glass is not mentioned. I cannot see colours shown for the later Walther production (but then I can't find the "Sonnenfisch" tray in the later catalogues at all - perhaps someone else can verify one way or the other).

Obviously, if pieces were to have been coated with colour post-production, then they must have been clear glass to begin with. On Pamela's website the majority of clear glass items seem to be plates. All the more decorative items appear to be coloured (and that is borne out by the catalogues which list those items in rose, amber, green and blue).

Glen

[Frank]

Reading up I find that etching was developed in Holland in the 1780's following the discovery of hydrofluoric acid in 1777.

There are for categories of decoration for the period we are interested in - upto the 1960's. (Heddle: Etching and Engraving Glass)

[list=1]
[*]Decoration with heat: Blowng shaping, applied ornament, flashing, double dipping, enamelling, staining and pressing.
[*]Decoration by chemical action: Clear acid embossing, deep acid, white acid etching, satin acid etching, French or triple embossing, fluoride pastes.
[*]Decoration by abrasion Cutting, Intaglio, wheel engraving, diamond point, sand blasting.
[*]Decoration by adhesive: Painting and transferring. (Permanence with firing.)
[/list:o]

Often combinations will be used.

Dietrich Mauerhoff presumably refers to 2 Fluoride pastes AND satin acid etching.

Lalique made extensive use of 1 staining and we would be well advised to consider that for early Walter. Staining was first used for stained glass and the main method uses oxide or chloride of silver. I will need to look elsewhere for what was used for different colours but it is best used on potash-lime glass. I presume that the Carnival spraying technique falls into the staining gategory.


Further research...

[Glen]

Just for info.........Carnival used to be called doped ware. Early ads also used to refer to it as "decorations burnt on, will not wash off"  :lol:

Glen

[Frank]

With other uses of doped I think that makes it very similar to staining, there are bound to be as many terminologies in this areas as in the rest of glass technology.

[pamela]

what do I do at a flee market in order to recognize: uranium glass or not?
sometimes I fail - but this is good and works, if you look in diagonal sense through the rim of the glass, and if you do, you will reckognize coloured Walther glass as brushed/painted as well

Following this, I take the Walther items in question - looking INTO the glass - and it becomes obvious
the Fische bowls of 0651 and 0642 are brushed/painted or whatsoever!
I am really clueless of how to name/explain this looking into a glass - here it works!

[Lustrousstone]

I think Pamela is getting confused. :?  No offence meant Pamela.    I think that the all-over colour items are coloured glass. The confusion arises when they have been painted only on the back with acid etching paste/solution, or whatever. When I look at the rim of my uranium bowl, which is frosted only on the back, I can see what Pamela means. It might be clear glass sprayed with green uranium BUT there are a few tiny shiny patches on the back that have not been etched and that are clearly still green. Unfortunately I don't have any other Walther colours to look at in the same way. Maybe Glen can understand what I mean and help out with a bit of blue or something. I think the shiny on one side and matt on the other was to give depth. My all-over matt Nymphen trinket bowl looks quite flat next to my shiny on the front large bowl  (whose name I don't know but Pamela has a Pelikan in hers).