Topic: terminology: coralene, enamel, frit (split from Dartington vase thread)

[krsilber]

This thread is being started to address some terminology issues raised in this thread, http://www.glassmessages.com/index.php?action=post;topic=17576.0;num_replies=11, particularly this comment by Ivo in response to a couple statements of mine:

"frit coated surfaces"  is usually referred to as "coralene" or "Mathey crinkles". Your creamer is the former.
Enamel in glass terms is coloured glass powder - get used to it.

The coralene I'm familiar with is made of small glass beads applied to cold glass with clear or colored enamel.  My creamer doesn't have beads; looking through a loupe it appears to be finely ground glass or frit applied directly to the object and fused. 

Why should I get used to a definition of a very common glassmaking term like "enamel" so obscure that I've only ever seen it used by a couple members of this forum?  Where else is it used this way?

When most Americans think of enameled glass they think of colored painting, and from what I gather the same is true in Europe.  If all enamel were simply colored glass powder it would be difficult to apply with a brush and wouldn't fuse at a temperature low enough to avoid the risk of softening the object to which it's applied, or at least causing stress to it, as reheating an annealed object does.  Typical enamels (at least of the last few centuries) contain crushed glass/frit, metallic oxides, a flux to lower the fusion temperature (e.g. borax or lead), and an oily substance to suspend it in so that it can be applied with a brush.  The painted object is heated in a low-temperature muffle kiln to fuse the enamel to the glass.

There may be other correct definitions of enamel.  My point it that this definition is by far the most common one, and it can be confusing to use the term to describe other applications when it is just as easy to use different terms for those applications.  "Ground glass" is simple, descriptive, and hard to misinterpret. 

I think I've been using the term "frit" wrong, as synonymous with "ground glass."  I'm still a bit confused about its uses beyond enamels.  What is the reason for using something partially fused vs. entirely fused?

[Ohio]

Frit: Some of the ingredients used in making glass such as cullet (first melted to remove impurities) sand & alkali, preheated in a calcar (but not to such a high temperature to completely melt or fuse them) cooled & ground into a powder which is added to the batch to be melted into glass. Glass A to Z, Shotwell 2002.

Now I'm not certain I understand your point Kristi, but I've come to the conclusion that Americans & Europeans use different terminologies/definitions when it comes to glass making, techniques used, etc. & I do not consider one to be more correct, accurate, superior to another, whether American or European. I do not believe in the necessity of one all encompassing definition for whatever technique, material, process, etc. when it come to glass...we (Americans) have our definitions/reasons & Europeans have theirs.

To me enamel is paint. Frit is ground glass used in products such as Dugan's Art Glass line. Thats my view as an American collector, however this does not mean that European collectors would agree/disagree because they have their own reasons for their glass nommenclature. Both should simply be embraced for what they are & accepted as they are meant to apply to whichever side of the Atlantic the collector hails from. Ken 

[Ivo]

you could start by distinguishing between the various type of enamel:

- cold enamel : decoration technique for glass using a (usually matt) paint which is not fired on and therefore will wear off with time.

- hot enamel: decoration technique using ground coloured glass in a (usually oil) suspension which is applied and fired on in a kiln

- vitreous enamel:  a smooth, durable coating made of melted and fused glass powder;

   in glass making: glass based colourant for use in glass blowing (marvering) and glass refining (hot enamel)

 There is no need to simplify the definitions, thank you.

[Frank]

Partially fused would be that the material has bonded to the substrate but not completely homgenised the result has a coarse texture, whereas completely fused the surface is smooth to the touch. There may well be more defined terms for this.

With the need to conserve energy it will become an outdated technology and colours will be fused to glass with UV. This is being spearheaded in the container industry and makes such a significant energy cost saving, as well as workplace and environmental health benefits, that it will rapidly spread to the rest of the glass industry as the technology investment cost drops. For the artist, especially in stained glass, it will totally transform what can be achieved with high quality images transferable from the computer to any glass surface/shape - combined with holographic technology, imagine a church window that changes shape as you walk past it. Glass decorators will no longer need expensive kilns with massive energy costs.

[Adam]

So far as the UK is concerned, Pilkington Brothers were unique in using the word "frit" to mean the same as what everyone else called "batch", i.e. the mixed raw materials ready for charging into a furnace.

Adam D.

[krsilber]

you could start by distinguishing between the various type of enamel:

All definitions and descriptions of enamel I've read with the exception of one in your book, Ivo, include firing.  Otherwise it's paint.  All enamel is vitreous since it includes glass in its composition.  I'm not simplifying definitions, I'm simply repeating the definition I've read many times.

Ken, I'm basing my definition on both American and English authors; they are the same.

Frit: Some of the ingredients used in making glass such as cullet (first melted to remove impurities) sand & alkali, preheated in a calcar (but not to such a high temperature to completely melt or fuse them) cooled & ground into a powder which is added to the batch to be melted into glass. Glass A to Z, Shotwell 2002. 

That's the first definition I've read that includes cullet.  Why would it be melted to removed impurities, when it was already molten glass at some point?

(Has anyone else noticed that many of the definitions in Glass A to Z are virtually identical to those in Newman's?)

I should have expanded on my confusion concerning frit.  According to CMOG, frit is "Batch ingredients such as sand and alkali, which have been partly reacted by heating but not completely melted. After cooling, frit is ground to a powder and melted. Fritting (or sintering) is the process of making frit."  I don't understand what the partly reacted by heating does.  Hmmm, maybe it's simply to burn off impurities?  Sometimes glass formulas call for "burnt sand" in order to accomplish that.  Or it's not melted because there isn't a flux in it, and it would need to be heated to a high temp to melt?  Something tells me the reason is more complex than that.  Frit used in enamel or for coloring glass by marvering presumably wouldn't need all the ingredients of a glass batch.  I've never seen a glass "recipe" that calls for frit - but then, though I've seen many, there are certainly hundreds of them I haven't.

So far as the UK is concerned, Pilkington Brothers were unique in using the word "frit" to mean the same as what everyone else called "batch", i.e. the mixed raw materials ready for charging into a furnace.

Adam D.

Ah, yes - there always seem to be companies that use a term differently from the rest of the world!   That probably explains a lot of the ambiguity in glass terminology - people see those oddball definitions and take them to be normal alternatives.

[Frank]

Which of course explains why you will never get to a single term for the same thing used universally. Just like the word blue. What is the normal term for one, is oddball for another, and you will get blue in the face trying to change it. I use different words for the same thing quite often too, must be that trace of blue blood.

[Ivo]

If you will not accept the answers provided I fail to see the point of this discussion. Go and find a library some place, and read.

[krsilber]

If you will not accept the answers provided I fail to see the point of this discussion. Go and find a library some place, and read.

Hee hee, nothing is more likely to get me arguing than a little condescension!

What are you, infallible, Ivo?  Or do you think I'm so ignorant that I don't have a right to disagree? 

I do read.  I read old and new books and patents, and online articles from a wide variety of sources, discuss things in forums, ask questions...I'm a very curious person.  And sometimes it gets me into trouble, but I'm a person who enjoys a friendly debate.  I want everyone to understand that to me this is not the same as an argument.  Debate can be very educational; it inspires people to read, learn, and ask questions, and shouldn't be hostile.


I have no problem with multiple definitions of words.  We all understand that "blue" means different things in different contexts.  I have no problem with people using different words to describe the same thing.  Heck, I lived in Australia!  I know about the variability of language.

My whole point is that communication is a good thing.  Good communication is not helped by using confusing terminology, and that includes using common words in uncommon ways that can be easily misinterpreted by your audience.  I just did a board search for "enamel" and of the dozen or so threads I read, the word always referred to painted colors.  (There was also this remark by Frank:  "But if the colouring can scratch it is unlikely to be enamel, and thus paint!"  I'm not the only one who has made that distinction.)  It just doesn't make sense to me to use that same word for another type of surface treatment when a more obvious word will do.

[Ivo]

do you think I'm so ignorant that I don't have a right to disagree? 

I couldn't possibly comment on that - but try googling cold enamel in stead of enamel - and maybe take up a hobby:
http://www.youtube.com/watch?v=bEfforZfNA8