Talk:Soft-paste porcelain

What is it?

Article omits to mention what SPP actually is!!!--Light current 04:09, 13 March 2006 (UTC)

Good point! I'm add something to the entry Regards, Andy

suffers heavy kiln losses

Can anybody please be more specific? What is the problem with this temperature/process?

Reason for change

With the very occasional exception glass, and even frit, have not been used to produce soft paste porcelain for 100s of years.

Regards, Andy

• Everybody started using a blend of hard-paste after WWII. Asian clay was abundant and easy to find now that the Pacific rim was open to the Western world. There are even prepackaged blends of porcelain sold by by the ton by major manufacturers - JUST LIKE COFFEE! --Emana 21:12, 27 February 2006 (UTC)

Ceramic stub

Tellyaddict: please do not delete this contribution again. The comment about the stub is to highlight a mistake: soft paste porcelain china is far more widespread a subject than to be covered by a single, art dedicated stub. The subject is diverse, and covers areas including antiques, industry, art and materials science

First, please register and sign your comments. You've already logged in from two different IP addresses and this causes confusion. Second, I agree that this article is very brief. What do you propose we do? Do you have any reference materials you can point writers to, regarding the use of this material in the fields you have mentioned? Please feel free to contribute to the article yourself. --Emana 19:21, 18 December 2006 (UTC)

Porcelain classification

I've added a bit about the history of soft paste and methods of making. I've removed the reference to soft-paste as a type of porcelain: although it is historically and currently called porcelain in a loose sence, in a strict sense it is not porcelain at all but an imitation of porcelain. This sometimes misunderstood. Indeed, the external link is confused about it, and as soon as I can find a better once I'll replace it! Marshall46 18:13, 11 January 2007 (UTC)

Hello Marshall 46, I have reverted your earlier changes as you had based this on one inteepretation of soft-paste porcelain (i.e. frit compositions). There are other widely accepted interpretations of hard-paste / soft-pasteTheriac 18:24, 11 January 2007 (UTC)

Hello, Theriac. The issue is whether ceramics are best classified according to the nature of their materials or according to historical usage. My revision was based on the nature of the materials - not simply the presence of frit in soft-paste but on the difference in the firing temperature between hard-paste (around 1300 deg. C) and soft-paste (no reference material available but I think always under 1100 deg. C). Taking a NPOV, I suggest that the article should point out that common usage classfies soft-paste as a porcelain, but that there are differences between soft-paste and hard-paste that affect the method of making, treatment in the kiln, economy of production and nature of the finished item. To say that soft-paste "is a type of porcelain" without qualification is not NPOV.

That being agreed, I cannot understand why you have taken out my revision about method of making and decorating. It is universally accepted that the decoration of soft-paste is what makes it attractive to buyers, collectors and art critics, and certainly, in the absence of an illustration, that ought to be mentioned. Marshall46 18:46, 11 January 2007 (UTC)

Marshall46 you are technically correct in pointing out that what we call "soft-paste porcelain" today is not really porcelain, but rather a man-made immitation of "porcelain". To call "soft..." a type of "porcelain" is not violating NPOV, but rather like calling all polymers "plastic" - just a plain misconception. I also agree about including what makes "soft..." special, and why it was used even after "hard..." became popular. I will rewrite the opening sentence and incorporate some of your content that was reverted IF YOU COULD CITE SOME SOURCES. --Emana 23:47, 11 January 2007 (UTC)

Thank you, Emana. I think your edit improves the article. I will seek sources for my passage about making and decoration. A section on history is now needed, referring to important makers like St Cloud, Bow, etc. A picture would be useful. Marshall46 08:12, 12 January 2007 (UTC)

Hello Marshall46 (+ all), I was a little extravagent with the extent of by revert so please excuse the wholesale removal of the making & decoration reference. I'm sitting here with a coffee just before strating work so I can not devote too much time at present but I come back later. I have, however, deleted 'man made' as this doesn't make sense as all porcelain, irrespective of formulation and manufacturing technique is man madeTheriac 08:46, 12 January 2007 (UTC)

Theriac, You're correct. Unless miraculously found pre-mixed, every formula of porcelain is man-made. I wanted to set the tone with something that signified that it is not the "original formula" but not inferior, just different. Like diet v.s. regular. Do you have any ideas? -- Emana 20:22, 12 January 2007 (UTC)

Hello Emana,

Thank you for the reply. I think I can see what you mean, but (1) pre-mixed, unfired bodies do naturally exists, and are known as Pottery or Porcelain stones. Although these days they are generally mixed with other raw materials they can form porcelain, (2) these still need to be fired to form porcelain. Without this essential step, which requires human intervention, they can not be classed as porcelain. ThanxTheriac 13:15, 15 January 2007 (UTC)

Theriac, So "porcelain" is the fired product? I guess that makes sense. The mixture of flour, eggs, and chocolate is not a chocolate cookie, it is the baked product that is the "cookie".

Yep I'd go for that. Before firing / baking the materials are not ceramic / cookies, but only become so after the reactions that occur at high temperatureTheriac 19:17, 15 January 2007 (UTC)

Formulation

I have doubts about the sentence, "Formulations were later developed based on kaolin, quartz, feldspars, nepheline syenite, and other feldspathic rocks." (1) Aren't those formulations for hard-paste porcelain? (2) Nepheline syenite is a type of feldspar (NaO.Al₂0₃.4Si0₂), and I'm not sure what is meant by a "feldspathic rock". I've marked this . Marshall46 10:55, 14 January 2007 (UTC)

Hello Marshall46, I can see nothing wrong with the sentence. (1) such raw materials can be, and are, used to formulate both soft-paste and hard-paste. (2) Nepheline syenite is not a feldspar, (3) an example of a feldspathic stone used in ceramics is China stone (also known as Cornish or Cornwall stone).ThanxTheriac 13:22, 15 January 2007 (UTC)

So, I'm sure the next question would be, "What is the difference between soft-paste and hard-paste porcelain"? Is it only the pyroplasticity at certain firing temperatures that make the difference? I was under the impression that Asian porcelain where the addition of minerals was minor was considered hard-paste and European porcelain where it was almost wholly man-mixed was soft-paste. But then, that wouldn't explain why it's "soft". I wonder who started calling it that way. -- Emana 19:12, 15 January 2007 (UTC)

Quoting from Singer & Singer (tt's getting a little long in the legs but it's still a very worthwhile reference)

Soft porcelain is the term covering a number of different bodies that are all vitreous, white and translucent. They vitrify below cone 12 and most are vitrified in the biscuit firing and subsequently glost firing at a lower temperature. They are subdivided according to the raw materials:

• Seger Porcelain, American Household China, British Electrcial porcelain - these are all bodies made up of china clay, some ball clay, flint or quartz and feldsapr or Cornish stone or nepheline syenite. They form a continuous series with the lower fired hard porcelain and also vitreous china.
• ''Frit Procelain, Belleck China, American Fine China (no more types listed but I’ve left further detail out)
• Dental Porcelain (no more types listed but I’ve left further detail out)
• Parian Ware (no more types listed but I’ve left further detail out)
• Jaspar Ware (no more types listed but I’ve left further detail out)
• Basalt Ware (no more types listed but I’ve left further detail out)'

(reference Industrial Ceramics. Singer F. & Singer S.S. 2nd edition. 1971)

Theriac 19:32, 15 January 2007 (UTC)

Emana asks who first called it "soft paste"? The French makers in the 18th century called it pâte tendre. As it's fired to a lower temperature than hard-paste, it is softer - the books talk about being able to scratch it with a file.

In the pottery industry soft-paste is a mixture of clay and glass frit and hard paste is a mixture of clay and feldspar. Soft-paste was originally made by the factories at Saint-Cloud, Sevres, Chelsea, Derby and Bow. Hard-paste was originally made by the factories at Meissen, Plymouth and Bristol. British makers of domestic and decorative porcelain now make only soft-paste, while hard-paste is made in continental Europe.

Theriac's quote from Singer and Singer does not seem to recognise this distinction. They say that “Soft porcelain is the term covering a number of different bodies that are all vitreous, white and translucent. They vitrify below cone 12 and most are vitrified in the biscuit firing and subsequently glost firing at a lower temperature.” They include in soft porcelain “bodies made up of china clay, some ball clay, flint or quartz and feldspar or Cornish stone or nepheline syenite.” Such bodies are often classified as hard-paste.

W.B.Honey, in European Ceramic Art (Faber and Faber, 1952), distinguishes soft-paste and hard-paste porcelain as follows. Of soft paste he says, “many successful and artistically very important imitations of true porcelain were made in the 17th and 18th Centuries by the use of glass or the materials of glass fused and ground-up and mixed with a clay or other substances to give whiteness and a degree of opacity.” (p.496). Of hard-paste he says, “It has been argued that the term porcelain having been applied originally to the Chinese material can only be used of others essentially similar in composition, that is to say, to compounds of the practically infusible kaolin (china-clay) and the fusible feldspathic petuntse (china-stone), two kindred materials which combine, when fired to a temperature of 1300oC-1400oC, to form a white more or less translucent vitrified material . . . ” (p.495)

Writers on ceramic art agree on this distinction between soft-paste and hard-paste. From Theriac's reluctance to accept this distinction, I surmise that writers on materials science and other industrial ceramics (with which I am unfamiliar) take a different view and do not permit such a tidy distinction. If that is the case and there is no unanimity, the articles “Porcelain”, “Hard-paste” and “Soft-paste” should be merged and the different approaches acknowledged. Marshall46 16:07, 16 January 2007 (UTC)

Hello Marshall46. I hope you do not think me to be argumentative but:

• Whilst you are correct to state that “Such bodies are often classified as hard-paste.” they are also often classified as soft-paste. This is why Singer & Singer note that “They form a continuous series with the lower fired hard porcelain and also vitreous china.” This highlights that the division between hard paste and soft paste is sometimes difficult. However generally, and exceptions can always be found, hard paste is fired at higher temperatures than soft paste, and often in a reducing atmosphere with soft paste in oxidising. The glost temperature of hard paste is invariably higher than its biscuit whilst for soft paste this is often the reverse

• Singer and Singer does recognise the distinction of different soft paste porcelain. The clay / glass frit compositions are included in the “Frit Procelain, Belleck China, American Fine China” sub-group of Soft paste porcelain

• Although historically I would agree with “British makers of domestic and decorative porcelain now make only soft-paste, while hard-paste is made in continental Europe.” Sadly the UK industry has suffered and production of any porcelain is on a diminished extent

• W.B.Honey is a being imprecise with his description. Regarding petunse as 1) these can be both feldspathic and micaceous in composition, and 2) China-stone is a term that is typically reserved for a rock unique to Cornwall. It is not synonymous with petunse, which itself is a name that has long fallen out of use

• I can not agree with your statement “In the pottery industry soft-paste is a mixture of clay and glass frit and hard paste is a mixture of clay and feldspar.” as in my experience there are many formulations that use clays+quartz+feldspar that are described as being soft paste. Again this is recognised by Singer and Singer

• I personally think it naïve of W.B.Honey to suggest that “porcelain .. can only be used of others essentially similar in composition” as it can be exceptionally difficult, and sometimes impossible, to identify what raw materials were used after an article has been fired. I wonder how, especially in the early 1950s, he was so confident to know what raw materials were used to produce all ancient Chinese porcelain

• I would agree that soft paste is so called because of its mechanical properties after firing (“scratch it with a file”) However the article refers its description to its pyroplastic behaviour

• I can see value in acknowledging that there are different interpretations of soft paste and hard paste

Again I hope you do not think of me as argumentative. I wish simply to use the discussion page for discussion :-) Theriac 16:49, 16 January 2007 (UTC)

I can see that the historical approach to soft-paste (which I take) and the analytic approach (which you take) produces different results. A Wikipedia article should reconcile different approaches to a subject if they are current and widespread, or, if they are irreconcilable, describe them with sources.

You have cited Singer and Singer (which I do not know), who not unreasonably say that porcelains form a continuum from harder to softer. I think that that analysis belongs in the main article “Porcelain”. Every writer on the history of ceramics (i.e. tableware and decorative wares) that I have ever read defines soft-paste as I do. This usage is so well established that it must form the basis of an article about soft-paste porcelain. Dental and electrical porcelain do not come into it. To put the continuum of porcelains at the centre of this article, which I think you are trying to do, is misleading, and, if I may say so, pedantic.

There are many articles about porcelain in Wikipedia. Some stand alone and some should be combined. This disagreement about the definition of soft-paste and hard-paste suggests to me that they should be combined into the main article, which can include the various definitions of porcelain (from art history, the pottery industry, studio pottery and materials science) and then have a historical section on the invention of soft-paste, Sevres, Chelsea, and so on. Responses, please. Marshall46 19:52, 16 January 2007 (UTC)

Hello Marshall46, I am pleased that we have agreement that there are differences in the usage of hard paste and soft paste. But I can not agree that “defines soft-paste as I do” “must form the basis of an article about soft-paste porcelain.” The article, as it currently is titled, is about the whole topic of soft-paste. To omit that the term is used to refer to a wide range of formulations would be misleading. For stand alone articles (and at the moment I am not sure why there is need for one. Referring back to an earlier term, I believe it was Nick, I favour lumping) the frit compositions could form the basis of an article about the early soft-paste porcelains. I would not dispute that many from the historic viewpoint of ceramics define soft-paste as you do. Equally though many who study the material, and produce it, use the definition to which I subscribe.ThanxTheriac 20:13, 16 January 2007 (UTC)

OK, how 'bout we do this. Include both interpretations where Marshal46's part would start something like "Historically, soft-paste porcelain is known as..." and Theriac's part would then add to it with "Today, with a wide variety of artificially formulated porcelain available, soft-paste porcelain has taken on a different meaning...". Each of you could add a blurb into the General section, then create sections for History vs. Modern History with subsections including Artistic usage and Formulations -- Emana 21:34, 16 January 2007 (UTC)

Hi Emana. Yep, I'd go with your suggestionsTheriac 08:01, 17 January 2007 (UTC)

Theriac must give more sources. So far he has cited only Singer and Singer in a reference to soft porcelain (which is not the term under discussion). I take the view that the term "soft-paste porcelain" is used universally to mean the mixture of clay and glass frit developed by the potteries of Sevres, Chelsea, etc. I am open to persuasion in the face of other citations, but I have never seen the term "soft-paste pocelain" applied to all all porcelains that may be accounted soft on some objective measure. A reader looking up "soft-paste porcelain" can reasonably expect to find an article that follows all the published accounts on the subject. Wikipedia is not the place for new definitions. Marshall46 15:46, 17 January 2007 (UTC)

Hello Marshall46,

A reader looking up "soft-paste porcelain" can reasonably expect to find an article that considers all significant aspects of the subject. This includes to what the name refers, and what the material is. And for these there can be differences across fields of study

It is acknowledged that for some people “soft-paste porcelain” can mean frit compositions alone. But the useage of hard-paste and soft-paste I have previously described are not “new definitions”, and this can be seen from the reference I have already given. Singer & Singer is a respected reference book, its second edition was published in 1971 with the first edition in 1962. The useage is also established in industry.

For another reference please refer to “An Introduction To The Technology Of Pottery” 2nd edition. Rado P. Pergamon Press. 1988. It is noted that the author, Paul Rado, was formerly the Research Manager at Royal Worcester. On page 181, the chapter titled “2.2.2 The Soft Porcelains” the opening paragraph starts “Soft porcelains, or soft paste porcelains ..” The chapter is split into three sections: Frit porcelains, Magnesia Porcelains, High feldspar porcelains. About the latter he notes “Bodies consisting of the three classical ingredients make up a large group of the soft porcelain, in the approximate proportions of 30-40 per cent clay substance, 25-35 per cent quartz, and 30-40 per cent feldspar. Some ceramists apply the term soft porcelain to this group alone.” There are three further paragraphs on these high feldspar compositions, and included are specific examples like Seger Porcelain, Japanese porcelain, Parian and English Translucent China. Nepheline syenite is also mentioned as an alternative raw material to feldspars

Theriac 16:48, 17 January 2007 (UTC)

Theriac is confusing soft-paste with soft porcelain. The discussion of soft porcelain belongs in Porcelain, not here.

Writers on the history and techniques of ceramics consistently (and I am inclined to say unanimously) use the term “soft-paste porcelain” to describe a mixture of clay and glass, in contrast to other types of porcelain that contain kaolin (china clay) and feldspar. In forty years I have never seen the term used in any other way. Here are a few examples:

" … soft-paste glassy porcelains … " Bernard Leach, A Potter's Book (Faber and Faber, 1940) p.40.

" … porcelains made with glassy substances, known as soft-paste … " W.B.Honey, European Ceramic Art (Faber and Faber, 1952) p.495

"Soft-paste … the body contains a high proportion of glassy frit." Frank and Janet Hamer, The Potter's Dictionary (A&C Black/University of Pennsylvania Press, 2004) p.273.

"Soft paste. A general term for all the experimental and glassy bodies which were developed in Europe from the time of the Medicis to the end of the eighteenth century." Robert Fournier, Illustrated Dictionary of Practical Pottery (Van Nostrand Reinhold, 1973) p.214.

"… soft pastes all included a fair proportion of glass in their formulas.” [1]

"… 'soft paste', composed essentially of glassy matter mixed with white clay." Arthur Lane, English Porcelain Figures of the 18th Century (Faber and Faber, 1961) p.3

"They eventually developed soft-paste porcelain by using mixtures of fine clay and glasslike substances." [2]

"Soft-paste porcelain is produced by mixing white clay with 'frit' - a glassy substance that was a mixture of white sand, gypsum, soda, salt, alum and nitre." [3]

"… pâte tendre. The ingredients used were such things as sand, gypsum, and soda which were fused together in blocks and ground to powder. To the powder was added a mixture of chalk and clay.” George Savage, Porcelain Through the Ages (Penguin Books, 1963) p.181

"Soft paste: a type of non-feldspathic, glass-like porcelain developed in Europe in the eighteenth century, largely by factories unable to produce true Oriental or hard-paste porcelain." Paul Atterbury (ed.), The History of Porcelain (Orbis, 1982) p.243

"In 1678 at St Cloud a soft-paste porcelain was developed … a glassy frit was used as a flux, instead of feldspar." Sasha Wardell, Porcelain and Bone China (Crowood Press, 2004) p.11

"Soft-paste Porcelain. It is made from a mixture without kaolin. Soft-paste porcelain must not simply be equated with 'soft' porcelain because this latter term describes porcelains with a low percentage of kaolin. Basically the East Asian porcelains, with a kaolin percentage of 20-30%, are 'soft porcelains' compared with the European 'hard porcelains' that have 50-55% kaolin. Firing temperatures are not very different: European hard porcelain is fired at 1350-1450^oC, soft porcelains required 1100-1350^oC, and soft-pastes a mere 1000-1200^oC." P.W.Meister and H.Reber, European Porcelain of the 18th Century (Phaidon, 1983) pp.12-13

However, I am open to persuasion if anyone can cite sources that do use "soft paste" to refer to bodies with kaolin or feldspar, or to refer to other types of ceramic, such as dental and electrical porcelain. Otherwise, I will edit the article accordingly.

Hello Marshall 46.

• I am not confusing soft-paste with soft porcelain. I understand the term to be synonymous. This is also established practice in industry. The Rado book I listed earlier is a citation for this useage
• ”Writers on the history of ceramics may consistently use the term “soft-paste porcelain” to describe a mixture of clay and glass.” But writers on the techniques do not
• The references you give support the view that Writers on the history of ceramics subscribe to just the frit based definition. I have given references to other views
• How can you state “unanimously” when there are references that give an alternative view?
• ”In forty years I have never seen the term used in any other way.” That is your experience, but it is not mine. And neither can find a place in the article
• You say “I However, I am open to persuasion if anyone can site sources” But I have!
• Please do not “edit the edit article accordingly." The article is not yours. Please refer to the Wikipedia entry on itself “Wikipedia is written collaboratively”
• The article would only benefit for it to acknowledge there are differences in useage

Theriac 19:34, 18 January 2007 (UTC)

Hi, Theriac. Unfortunately I don't have the two books you cite so I can only go on your quotations from them. Both treat frit porcelain (i.e. soft-paste) as a type or sub-class of soft porcelain, which is consistent with what I am saying. Neither treats soft porcelain and frit porcelain/soft-paste as synonymous.

I have spent a long time on this and this is the last thing I shall say before removing the errors in the aritcle: the relationship between soft porcelains and soft-paste is the same as the relationship between team sports and soccer; just as the article on soccer doesn't need to refer to other team sports, so the article on soft paste doesn't need to refer to other soft porcelains. Marshall46 16:12, 20 January 2007 (UTC)

Hello Marshall46. You are correct neither of the books I referenced treat frit porcelain and soft-paste as synonymous. What they do treat is frit porcelain as a type of soft-paste porcelain, along with other formulations types. As I have noted before please do not edit the article to reflect you own personal view, or that of a single field of study. Please refer to “Wikipedia is written collaboratively”ThanxTheriac 17:20, 20 January 2007 (UTC)

Added later: the following quotes may be of interest, as they are references to that some writers consider what I believe you would called soft-paste porcelain can also be called soft porcelain

• "Soft porcelain includes the artifical (sometimes frit) porcelain, Seger porcelain, and bone china. “Ceramic Chemistry. H.H.Stephenson. Davis Bros. 1912"
• “The soft or tender porcelains were originally devised to imitate Chinese porcelains, but as those engaged in this work had not sufficient knowledge, the imitations differed very greatly from the original. Most of these soft porcelains contain more “glassy” matter than hard porcelain, and in some a frit is one of the chief constituents. The soft porcelains are much more fusible than hard porcelain, and lack some of the beauty of the latter. The chief varieties of soft porcelain are bone china, viteous porcelain, including new Sevres porcelain, Seger’s porcelain, parian ware, and soft feldspathic porcelain. Many others have been made in small quantities, but are of no industrial importance.” A Treatise On Ceramic Industries. 4th edition. E.Bourry.Scott, Greenwood & Son. 1926.

These add support to my previous staement that some fields of study consider "soft-paste porcelain" and "soft porcelain" to be synonymous.Thanx--Theriac 18:42, 20 January 2007 (UTC)

Hello Marshall46. Thank you for the re-write that acknowledges differences in useage. I have just amended it slightly:

• Trying to make the opening paragraph neutral
• Removed the ‘citation’ request against the quartz, feldspars, nepeheline syenite as these are now included
• Removed the bit about computer controlled kilns, not least as these formulations were in use before computers
• Removed the ‘citation’ request against the lower fuel consumption. The reason is that soft-paste / soft porcelains, irrespective of the raw materials used be it feldspar or frits, are fired to lower temperatures than hard-paste / hard porcelains. I think on that we agree. It is obvious that lower temperatures require less fuel

ThanxTheriac 15:53, 21 January 2007 (UTC) Added later: I forgot to note that the "'lacks an universally" bit I nicked from Nick (-: over at the Pottery discussion page, and I also included typical temperatures for the feldspathic typesTheriac 16:02, 21 January 2007 (UTC)

Good - we are getting somewhere!

For perfect balance I will add citations for the "glassy porcelain" usages as well as the "all soft porcelain" usage. Would you please add the page references to the citations of Bourry, Rado, Singer & Singer and Stephenson?

Hi Marshall46. I have tried to add the citations but have struggled. I think you may be better than me at this so if you could add:

• Rado, pages 181 - 184
• Bourry, page 454
• Stephenson, page 42
• Singer & Singer, pages 451-457

ThanxTheriac 12:49, 22 January 2007 (UTC)

I am doing some more work on the history section and will edit shortly.

Marshall46 09:49, 22 January 2007 (UTC)

Theriac, about "low fuel consumption". How do we know that really? Did someone do a side-by-side study of firing duration, temperature fluctuation, controled pressure, fuel type, etc.? I DO agree that IF ALL OTHER VARIABLES ARE THE SAME, lower temperature means lower fuel consumption, but we need to find a source that says so... and us three agreeing on a fact isn't reliable enough. -- Emana 17:34, 23 January 2007 (UTC)

Hello Emana. Yes people, including me, have studied lowering firing temperatures to gain fuel savings. It seems such an obvious relationship I am surprised you think it worth hunting down a citationTheriac 17:59, 23 January 2007 (UTC)

I myself know first hand what lower temperatures mean in manufacturing. It seems like an "obvious" relationship, yet nature has always betrayed humans. I think it should just be noted that if all else remains the same, fuel consumption is lower, and that the end product still will not have the same characteristics as hard-paste porcelain. -- Emana 18:53, 23 January 2007 (UTC)

Notes on recent changes

Hello all, Recent changes have been

• “constituent materials were not widely available in the west” -> “before the constituent materials were widely available in the West.”
• “Because of its low firing temperatures and chemical composition, soft-paste porcelain posesses certain characteristics that are unique” -> The lower firing temperatures of oft-paste porcelain compared to Hard paste porcelain gives Artists and manufacturers some benefits, including a wider palette of colours for decoration and reduced fuel consumption
• Changed “The body is granular because the ingredients do not meld together unlike hard-paste porcelain.” To reference glass formation
• Removal of “Therefore, water and other water-based substances (mainly paint) will permeate the body. This causes difficulty when applying flat colors to the body, of course unless an uneven mottled finish is desired. Therefore, applying a glaze is a simple and popular solution. Sometimes glaze is used on other ceramics to mimic products made using soft-paste porcelain.” I guess some will say I was harsh, but this statement suggests that soft-paste porcelain is not vitreous, which by definition it must be.

Theriac, Yes, all porcelain is vitreous to a certain degree, but soft-paste, because of its inherent softness, must be fired at lower temperatures. Therefore, the body is MORE granular than that of hard-paste porcelain that has been fired at higher temperatures. It is one of the reasons that glazing was so popular on soft bodies. Could you suggest a rewrite instead of a total removal? -- Emana 20:22, 12 January 2007 (UTC)

Notes on "misconception"

Hello Emana I am unclear about your statement “technically correct in pointing out that what we call "soft-paste porcelain" today is not really porcelain.” Could you explain why not? And why is calling it so “a misconception?” ThanxTheriac 13:44, 12 January 2007 (UTC)

Theriac, sorry. I was trying to defend you against an NPOV inquiry by another user. The misconception is that soft-paste "porecelain" is a misnomer that has survived the centuries. Like the sea cucumber is not a cucumber, the first people who named this substance should have picked a different name.

Hello Emana, Thank you for the reply. I was a little unsure about the comment as soft-paste compositions are certainly porcelain.ThanxTheriac 13:15, 15 January 2007 (UTC)

Making and decoration

Hello Marshall46, Thank you for the reply, and I hope you earlier response about “making and decoration.” With reference to your comment on temperature if it is to be included, and I am not sure if it would be advisable, it should note “up to 1400oC for hard paste” and for soft-paste it would be “up to 1250oC” I can see value in a historic section, and suggest that the different types of soft-paste are included, such as frit porcelain and feldspathic porcelain.ThanxTheriac 13:44, 12 January 2007 (UTC)

Also could someone include a fuller explanation of, or perhaps re-word, the following:

• “Because of its natural characteristics that differentiate it from hard-paste porcelain”
• “Soft paste porcelain is relatively soft”

ThanxTheriac 13:34, 12 January 2007 (UTC)

How about explaining why this substance is considered "soft" in the first place. When I got hit in the face with a soft ball, the first thing I thought was that it wasn't soft at all. Then I got hit in the face with a baseball and found out that it was indeed harder. -- Emana 20:22, 12 January 2007 (UTC)

I've restored the references to making, decoration and high regard among collectors. These are not in doubt, but I've noted that they needed sources.

As to firing temperature, I removed "relatively" from "relatively lower". I've recently seen references to 1100^oC and 1280^oC. If I can identify a consensus, I'll add a reference to this as well.

Do we need the phrase "pyroplastic deformation"? Robert Fournier (Illustrated Dictionary of Practical Pottery, 1973) defines it thus: "Long words to describe the warping or bending of ceramics as they 'soften' at high temperatures." Nice for us anoraks, but not necessary for the general reader, I suggest. If there are no objections I will remove it. Marshall46 09:52, 13 January 2007 (UTC)

Hello Marshall46, Pyroplasticity is the recognised term for the phenomena. Providing there is an appropriate explanation for anyone who does not it I can see more value in leaving than removing it.ThanxTheriac 13:25, 15 January 2007 (UTC)

I think "pyroplasticity" is an introductory level industry word that will encourage readers to read-on. Like the word "punt" for football makes readers think they understand a little bit about the game. -- Emana 18:57, 15 January 2007 (UTC)

Hello Emana, thanks for the comment. I would agree that "pyroplasticity" may also encourage further reading. Similarly other technical terms could be used, with appropriate explanation or links to other pages. I'm not sure I understand your "punt" analogy. Is this American fottball or proper football :-)Theriac 19:15, 15 January 2007 (UTC)

Ah, American football that is. Again, one of those things that the founders should have named differently. -- Emana 23:16, 15 January 2007 (UTC)

Lower fuel consumption

I have heard of "lower fuel consumption" as an argument that manufacturers use to choose to fire at lower temperatures of any ceramic. But is this why they would choose soft-paste over hard-paste? I guess it is a side-benefit of it. It would be interesting to see if there are any side-by-side research on it. BTW, hard-paste can still be fired at lower temperatures to form less vitreous bodies for glazing and paiting in the classic European style. I read somewhere that M.I. Hummel does that now. -- Emana 20:47, 12 January 2007 (UTC)

History

I am starting a section on the history of soft-paste manufacture. Marshall46

Great! The book, English Ceramics, by George Savage seems to have been thrown around several publishers. Can you include the edition and publisher for the bibliography? -- Emana 21:33, 12 January 2007 (UTC)

More on history added. Marshall1946 09:08, 25 February 2007 (UTC)

The section could definitely be expanded, and perhaps move the history section to the top?--Balthazarduju 20:02, 27 September 2007 (UTC)

Commercial link

Hell Marshall46. You will have noticed that ysterday I again removed the link which you had reverted. This is simply that its inclusion would contravene the policy of having no "Links to sites that primarily exist to sell products or services"Thanx--Theriac 18:59, 20 January 2007 (UTC)

Images and graphs

This article probably needs some graphic illustrations or something along the line.--Balthazarduju 19:48, 27 September 2007 (UTC)

Hotwater60 (talk) 18:13, 3 October 2011 (UTC)== Error in photograph ==

The photo used for Paul Hannong shows his faience (tin-glazed pottery) and is not porcelain. — Preceding unsigned comment added by Hotwater60 (talk • contribs) 18:11, 3 October 2011 (UTC)

Error in photograph

The photo used for Paul Hannong shows his faience (tin-glazed pottery) and is not porcelain. Hotwater60 (talk) 18:15, 3 October 2011 (UTC)

Removed. Marshall46 (talk) 16:23, 6 October 2011 (UTC)