What is Softpaste Porcelain
This article is an explanation of what soft paste porcelain actually is, & what it is made from.
From the 1600's Western merchants had begun to trade with their counterparts in the East, with large trading ships known as supracargoes taking goods from Europe out to China, & once the cargoes had been sold returning laden with Chinese goods.
Amongst these goods was Chinese porcelain, a ceramic body that had been produced for probably a thousand years or more by the Chinese, but that was completely alien to consumers in England & Europe.
The Chinese porcelain had unique qualities that were lacking in European domestic ceramics such as it’s strength, ability to withstand boiling water, fine potting, & translucency. These properties were a result of the different clay & other raw materials combining & reacting together in the kiln to give the porcelain a new & different chemical composition.
Essentially what happened was that the body & glaze, which prior to firing were 2 distinctly separate substances, fused together in the kiln to produce 1 single new material, namely a true, or as it is sometimes called a “hard paste” porcelain.
This type of porcelain when chipped has the appearance of flint or glass in that there is no discernable distinction between the glaze & body – it is the same material through out.
English potters didn’t have the necessary knowledge or a readily available source of the right clay or other ingredients, and so they used other additives to produce an artificial or “soft paste” porcelain.
The names hard paste & soft paste reflect the fact that the English ceramic body was not as strong or robust as the Chinese porcelain, the Chinese porcelain does indeed have a body that is notably harder than it’s English equivalent.
The English porcelains (with a couple of exceptions) did not vitrify in the kiln as the Chinese porcelain did, so that the glaze & body remain as 2 separate materials even after firing, the glaze being a glassy coat over the ceramic body.
English soft paste porcelain when chipped has a granular appearance, the texture similar to that of a sugar cube, & the sandwiched layers of glaze-body-glaze are clearly visible, almost like a cross section of a stick of seaside rock.
It can be difficult at first to distinguish between hard paste & soft paste porcelain, & there is also the problem of Hybrid hard paste, a later English invention, & also bone china to consider, but really the only way to learn is to train your eye & get a feel for it by handling plenty of pieces of all types.
The early English porcelain manufacturers used a variety of different additives to create their porcelain, from china clay imported from the USA, to animal bone ash, to soaprock, a form of steatite, to “frit” a ground glass additive.
Below is a list of who made which kinds of porcelain:
Hard Paste Porcelain:
There were a handful of English porcelain manufacturers who made a pseudo hard paste porcelain, namely Plymouth, Bristol (Champions), New Hall, & the “A” Class porcelain is considered by some to be a form of hard paste.
Champions Bristol bought the formula for their hard paste porcelain from Plymouth when that establishment closed, & similarly New Hall obtained the same formulas when Champions ceased production.
The “A” Class porcelains used imported unaker clay from “the chirokee nation” ie, the USA (now believed to have been early Bow using the first patent.
Frit Porcelains:
Chelsea, Girl in a Swing, Longton Hall, West Pans, Limehouse, & Baddeley Littler all made a frit based or glassy porcelain.
The “Girl in a Swing” porcelain is now known to have been made in St James by Chales Gouyn who had originally been involved with the Chelsea factory.
Longton Hall was established by William Littler, & when that factory closed he moved to West Pans in Scotland, apparently taking either undecorated pieces from Longton, or perhaps the moulds themselves since some wares have the same shapes as the Longton Hall predecessors.
Littler them moved onto Shelton where he helped Ralph Baddeley produce a similar glassy porcelain.
Bone Ash (phosphatic) porcelain:
The introduction of calcined bone ash into the porcelain body was used by a number of factories including Bow (2nd patent), Lowestoft, Derby, Isleworth, Gilbody (Liverpool), William Reid (Liverpool), James Pennington (liverpool), John & Jane Pennington (Liverpool), & Seth Pennington & John Part (Liverpool).
The bone ash porcelain often are quite thickly potted, sometimes with little translucency, & have a tendency to stain where there are cracks or flaws in the glaze. Ths is a result of moisture & bacteria getting under the glaze & staining the organic material.
Soapstone porcelains:
The addition of soaprock produced a very pleasing porcelain body that could withstand boiling water & could be thinly potted, it tends generally to have a greenish translucency.
Soapstone porcelain was made at Bristol (Benjamin Lunds), Worcester, Caughley, Vauxhall, Chaffers (liverpool), & Christians (Liverpool).
Benjamin Lunds factory in Bristol was bought by Worcester in order to obtain the formula, this was then obtained by Chaffers in Liverpool when Robert Podmore “defected” taking the formula with him. Philip Christian was partners with Chaffer, the factory simply changed names after Chaffers death.
Hybrid hard paste:
A number of factories adopted the use of hybrid hard paste porcelain, I will cover this topic in more detail in a future article.
Bone China:
Eventually the manufacture of soft paste porcelain dwindled as hybrid hardpaste porcelain became the favoured material, before eventually bone china, invented by Josiah Spode in around 1800 (& not improved in the 200 years since!) became the porcelain body of choice for English manufacturers because of its brilliant white body & translucency & its superior technical attributes.
There are a number of other helpful clues that can help to narrow down which manufacturer is likely to have made any given piece, I’ll cover those more in a future article.
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