Michelle Erickson and Robert Hunter
Swirls and Whirls: English Agateware Technology

Previously the authors reviewed the use of slips—liquid clays—to create a marbled effect on the surface of a clay object.1 In this article, we examine how two or more colors of clay are used to make a variegated ceramic body generally known as agateware. Although these two terms are sometimes confused, marbled decoration implies a surface treatment whereas agateware refers to a solid clay fabric.

Semiprecious stones, such as agate, are some of the most beautiful of all substances. They were prevalent as design elements in Chinese, Greek, and Roman societies and often associated with nobility. The use of multiple colored clays to imitate agate can be traced to antiquity as well. Beginning in the late seventeenth century, this technique was used to fashion a class of English ceramics recognized as agateware.

English agateware has been made for useful and ornamental purposes, collected, and written about for several centuries. However, only limited discussions of production methods have been published, which run the gamut from fairly accurate to wildly speculative. In addition, these descriptions have not contained illustrations of agateware techniques.2

Our approach to decoding and recreating English agateware began with the information contained in the actual wares themselves. Careful examination and considerable trial and error experimentation produced results that we are now able to demonstrate. Insights gained from this preliminary exploration should help frame further questions about the manufacture of agateware and its place in eighteenth-century consumer society.

Agateware can be divided into two broad categories: thrown agate and laid agate. Thrown agate describes a vessel formed on a wheel using a prepared mixture of various colored clays. Laid agate refers to an object created from a thin sheet or bat made of agate clay. This thin sheet is draped or laid in the mold and pressed into shape—hence our use of the term laid.3 Both types of agateware continue to be produced commercially as well as employed in the repertoire of the contemporary studio potter.4

History of Production
English Thrown Agate
The earliest documented agateware is found among the products of John Dwight (even though he himself referred to it as marbled). Considered by many as the father of English pottery, Dwight is well known in the annals of ceramic history for his innovations (fig. 1). He conducted numerous ceramic experiments beginning in the 1670s, delved into the mysteries of porcelain, and recorded his recipe to produce “marbled” stoneware:

  A dark colour’d Cley for marbled dishes and Teapots to endure boiling Water
   
  Take fine dark Earth ten pounds
fine white Earth Eleaven pound
Cley Sifted one & twenty pounds
White Sifted through Cyprus Sieve
Six pounds, mingle & tread

Included with the instructions are these comments:

  Note y t this dark colours; the mouse colourd, & the dish white Cleyes, agree best together to marke marbled Vefsells, that will burne Every where, & Endure boiling Water.
   
  But to make marbled gorges or Cans, the gorge white may be used instead of the dish-white, because it works Stronger upon ye wheel.5

Dwight’s notes reveal two important material considerations in making an agate body: clay color and clay compatibility.

To create the illusion of agate striations, different color clays must be obtained naturally or by modification, adding pigments or coloring agents. The tone of a natural clay can also be altered by sieving to remove impurities such as iron and sand.

Creating a successful variegated appearance also depends on the proportions of clay colors used. Dwight’s recipe required equal parts of dark (ten pounds) and white (eleven pounds) clay and an additional six pounds of white clay passed through a Cyprus sieve. Named for the silk material used for the mesh, this type of sieve had the smallest or finest opening available at the time. For the first of these colors, Dwight’s notebooks contain instructions for making “a dark earth”—a clay artificially stained with iron oxides obtained from the hammer scale of a blacksmith’s forge. The second color, the fine white, may be a natural pale- to mid-gray clay. Research shows that specimens of the final color—the six pounds of sifted white clay—are pure white and have virtually no macroscopically visible inclusions.6

Clues for understanding problems related to combining multiple clays are also contained in Dwight’s formula. These include shrinkage rates, firing temperatures, density, plasticity, elasticity, and strength. All of these properties must be considered when mixing dissimilar clay bodies.

When Dwight writes that these “dark colours; the mouse colourd, & the dish white Cleyes, agree best together to marke marbled Vefsells, that will burne Every where, & Endure boiling Water,” he is referring to the ability of clays to blend successfully to throw properly, to survive the firing without splitting or warping, and, as a finished product, to withstand the thermal shock from boiling water. In considering the agate clay’s working capabilities, Dwight prescribes that “the gorge white may be used instead of the dish-white, because it works Stronger upon ye wheel.” The term “Stronger” means that the clay could be better pulled up on the wheel and into a cylinder without distortion or collapse.

Today, only a few of Dwight’s “marbled” or agatewares survive.7 In addition, some agateware fragments have been recovered from archaeological excavations of his pottery site in Fulham. These fragments include examples of a tankard, a gorge (or mug), a cappuchine (coffee cup), and a teapot. The discovery of a teapot underscores Dwight’s concerns expressed in his recipe note that the clay could “Endure” boiling water.8

It is hard to judge whether Dwight’s agateware was received as a novelty or as an important scientific discovery. Evidence for the latter may be suggested by the “marbled” salt-glazed stoneware of Francis Place of York (fig. 2). Primarily an artist and engraver, Place was also a dilettante with eclectic interests, and he prominently included a mug in the foreground of his circa 1680 self-portrait. As part of a growing group of gentlemen-artists who studied every new artistic and scientific inquiry in English society, Place was undoubtedly inspired by the growing national interest in new ceramic discoveries which would lead to many technological breakthroughs in the eighteenth-century English ceramic industry.9

Commercial production of English agateware does not begin in earnest until the second quarter of the eighteenth century. In 1729, Samuel Bell, at the Lower Street potworks, Newcastle-under-Lyme, was granted a patent to produce “red marbled stoneware with mineral earth found within this kingdom which being firmly united by fire will make it capable of receiving a gloss so beautiful as to imitate if not compare with ruby.”10 Like Dwight’s agate, the Bell products were thrown on the wheel. After being initially formed, the wares were turned on the lathe to thin the body and concurrently create a clean variegated surface. These wares typically had a red and off-white clay body even though a black colored clay was used.

Contrary to the wording of the patent, Bell’s agateware is earthenware rather than stoneware. These wares are distinguished for being the earliest known twice-fired earthenware in Staffordshire, first being fired to a biscuit state then dipped into a liquid lead glaze and fired again. The wording in his patent “being firmly united by fire” may reflect Bell’s recognition of the potential problems of successfully integrating different clays into a single ceramic body.

Archaeological evidence from the excavation of Staffordshire factory sites, including that of John Bell and of John Astbury at Shelton Farm, shows that many potters made this type of thrown agate. Tea wares were the most common forms made, although mugs and bowls were also produced (fig. 3). Thrown agate reached its height of popularity in the 1750s and continued in production into the early 1770s.11

At that time, a coarser type of thrown agateware was introduced in Staffordshire. Used primarily for plates, dishes, and bowls, these wares frequently included rouletted bands of white slip decoration. This utilitarian agateware is commonly found in American archaeological sites of the 1770s and 1780s (fig. 4). Thrown agate production all but disappeared in Staffordshire by the late eighteenth century but continued sporadically in other pottery centers such as Sussex in the nineteenth century.12

English Laid Agate
The second quarter of the eighteenth century saw many innovations in the Staffordshire potteries. One of these was the use of molds for creating forms either by slip casting or pressing. Press molding permitted new possibilities for developing agate bodies (figs. 57).

Laid agateware is inherently different from thrown agateware in that the pattern must first be prepared before the shape is made. In other words, the decoration is made before the pot. It is uncertain exactly when the laid agate technique was developed in Staffordshire. Ceramic historian Simeon Shaw mentions Dr. Thomas Wedgwood of Burslem (1695–1737) as the earliest potter associated with the process. Apparently his products included “Coffee and Tea Pots, of clays compounded and mixed to resemble agate, marble, and other natural bodies, . . . in various shapes; some glazed with lead ore; and the white, all salt glaze.” Shaw continues, “Had the agate rising genius of that day been adequately encouraged, doubtless many important improvements would have resulted.”13

Another likely candidate is Thomas Whieldon of Fenton Low (1719– 1795). Whieldon is most often recognized for his improvements in agateware undertaken in the 1740s, including the use of white clays stained with metallic oxides.14 Still, a firm date for the beginning of laid agate in Staffordshire has yet to be established, although an agateware dish with the inscribed date of 1746 may be the earliest documented example that exists.15

Beyond the date of its introduction, however, the source of the laid agate pattern is perhaps the more important inquiry. Several writers have been hesitant to make this correlation, but, for us, it is clear that eighth-century T’ang dynasty Chinese wares inspired many eighteenth-century Staffordshire laid agatewares. The relationship is most obviously visible in the form of globular censers, or incense burners, which are of the same size and shape as the Staffordshire teapots (figs. 8, 9).16

The imitation of eighth-century Chinese ceramics by Staffordshire potters is not as improbable as it may seem at first. It is known that contemporary Chinese porcelains and Yixing stonewares served as direct prototypes for many eighteenth-century Staffordshire tea wares. It is likely that older Chinese wares resided in European and English antiquarian collections. Such antique wares were sought for the “cabinets of curiosities” of the English cognoscenti. Intriguingly, the cabinets belonging to these scientifically minded collectors often included “agates, onyxes and intaglios.”17

If Thomas Whieldon is responsible for deciphering the Chinese laid agate technique and introducing it in the Staffordshire potteries, he must have studied antique examples at length. In 1754, Whieldon entered into a partnership with young Josiah Wedgwood. Excavations at Whieldon’s manufactory at Fenton Vivian revealed a number of laid agate wasters, which appeared to have been manufactured during the period of the partnership.18 One of the most often cited agateware references comes from Josiah Wedgwood’s experiment book on March 23, 1759: “I had already made an imitation of Agat which was esteem’d very beautiful, and a considerable improvement . . . .”19 Just how much he improved the agateware process and whether he had a direct hand in copying Chinese prototypes is undocumented.

Josiah Wedgwood concluded his partnership with Whieldon that year and went into business for himself. He continued to refine the agate technology for decorating his ornamental vases. Wedgwood used both solid agates and marbled slip techniques at his Etruria factory into the 1780s. Rather than copies of Chinese prototypes, the vases were directly inspired by antique Etruscan and Roman examples.20

Agateware made on the Continent is occasionally confused with Staffordshire specimens (fig. 10). Close examination usually reveals both significant differences in the agate veining and vessel forms. In addition, the earliest known French agateware made by Francius Moulina and Jacques Barthelemy in Apt, France, beginning in 1768, was almost two decades later than the main production period in Staffordshire. Other laid agateware was made through the nineteenth century at several European centers.21

In the later part of the eighteenth century, some Staffordshire potters applied laid agate to utilitarian creamwares and pearlwares. Used in conjunction with mocha-type slip decoration, these examples had an agate sheet laminated to the surface (figs. 1113). This so-called surface agate or inlaid agate, although seemingly a laborious method of decoration, was still practical enough to embellish these inexpensive earthenwares.22

American Agateware
In America the use of agate clays is occasionally seen on domestically produced redware in the seventeenth and eighteenth centuries. Indeed, the earliest documented use of agateware technology comes with the circa 1650–1669 tobacco pipe kiln of Emanuel Drue in Maryland (fig. 14).23 However, the best-known examples of American agateware are the nineteenth-century products of the U.S. Pottery Company in Bennington, Vermont, termed “scroddled ware,” although the company called the ware “Lava” (fig. 15).24

A number of nineteenth-century American potteries used agate clays to manufacture doorknobs covered with a Rockingham glaze. In the twentieth century, agateware makes a brief appearance in the arts and crafts movement, most notably in the “Mission Swirl” line of the Niloak Pottery Company in Benton, Arkansas (fig. 16). Another thrown agate of this general type was produced by North State Pottery of North Carolina (fig. 17) in the 1920s and 1930s.

Demonstration of Agateware Techniques
Thrown Agateware Techniques
The key step in creating an agateware body can be summed up in three words: preparation, preparation, preparation! For creating thrown agate, the initial selecting and mixing of clays is critical (fig. 18). To begin, clay slabs are built up, alternating the colors (fig. 19). This stack is then wedged or folded to form a ball that can then be thrown on the wheel (fig. 20). Care has to be taken during wedging to ensure the clays are mixed without overly distorting or blurring the resultant agate pattern (fig. 21). The degree of success in an agate pattern comes from the initial wedging process as well as the throwing.

The prepared clay ball is then centered on the wheel (fig. 22). During throwing, the surface of the clay body becomes smeared so that agate patterning is obscured (figs. 2328). Care has to be exercised during throwing so as not to overwork the clay; otherwise, the pattern becomes muddled. Since nearly all Staffordshire thrown agate was subsequently trimmed on the lathe, the veining usually appears sharp and crisp (fig. 29). Later smearing and smudging can occur at the attachment points of handles or spouts as evidenced on some antiques.

Laid Agateware Techniques
Making a laid agate vessel requires a different set of skills than competent throwing. Deciphering the techniques behind the process required direct examination of extant pots and subsequent experimentation (fig. 30). Ceramic historian Pat Halfpenny wrote, “There is no 18th-Century manual on ceramic technology.” What we do have, instead, are secondary descriptions by ceramic writers since the mid-nineteenth century.25 One account by the ceramic historian Louis Solon explains the procedure:

  Agate-ware was a complicated process; the marbling, instead of being produced on the surface, went through the body. It was thus practiced: Thin laminae of yellow and red clay were laid alternately upon each other until they formed a thick mass; from that mass thin slices were transversely cut with a wire, making thin bats which showed the veining produced by the superimposed layers of clay; these were then used to press the piece, the neatest side being placed against the mould. The bat required careful handling, as a pressure sideways in the wedging in or a too rough pressing in the mould destroyed the fineness in the marbling.26

Agate-ware was a complicated process; the marbling, instead of being produced on the surface, went through the body. It was thus practiced: Thin laminae of yellow and red clay were laid alternately upon each other until they formed a thick mass; from that mass thin slices were transversely cut with a wire, making thin bats which showed the veining produced by the superimposed layers of clay; these were then used to press the piece, the neatest side being placed against the mould. The bat required careful handling, as a pressure sideways in the wedging in or a too rough pressing in the mould destroyed the fineness in the marbling.26

Solon’s description makes clear that the making of agateware is a “complicated” process. That his account is over simplified, however, is suggested by our research. As noted earlier, the initial preparation of clay is the key for creating laid agateware (fig. 31). Using naturally colored clays and those colored with metallic oxides, the clay slabs are first stacked in a selected sequence (fig. 32). Rather than wedging, the stacks are slammed onto a hard surface to elongate and consequently thin the slabs (fig. 33). The process continues with cutting and restacking the slabs, thinning and increasing the numbers of layers (figs. 3438). The ultimate success of the agate patterning lies in the care taken at this initial stage.

After these slabs of thinly layered clays are prepared, they are rolled into tight coils (figs. 39, 40). These coils are then arranged, sometimes by alternating colors, and carefully pressed into a single mass (figs. 41, 42). From this amalgamated mass, thin slabs are then cut and arranged on a flat surface to begin forming a sheet (figs. 4345). At this point, the outcome of the agate striations can be controlled by the placement of the slabs. Once a reconstituted clay sheet is made, it is cut into strips and reassembled to emulate the arbitrary nature of the agate pattern (figs. 46, 47). Examination of antique pots suggests that such strips were cut and rearranged several times on both a horizontal and vertical plane (figs. 4851). In working through this technique, it is clear that a number of variations are possible through the deliberate arrangement of the agate pattern.

Once a suitable agate pattern is created, the thin sheet of clay is ready for molding (fig. 52). In most cases, it appears that all elements of laid agateware were created by press molding (figs. 5358). This process requires a separate plaster or clay mold for each component of a pot. This would include the body, foot rim or feet, lid, finial, spout, and handles. As with the thrown agate, joins may show smearing, or distortion (figs. 5962).

Discussion and Summary
We hope this overview of English agate techniques will provide the basis for continued research. The laid agate technique is an extremely complicated procedure. Indeed, the replication of the processes presented here required nearly two years of trial and error research.

A rich opportunity exists to further study the production history of English agateware. Although Josiah Wedgwood’s “marbled” vases inspired by classical antiquities have been discussed at length in the literature, the origin of the Staffordshire laid agate techniques needs further examination. In addition, as we have demonstrated, a great deal of idiosyncratic behavior is reflected in the agateware process. For thrown agate this behavior manifests itself in the initial mixing of clays and the orientating of the prepared clay ball on the wheel. In her recent studies of the agateware fakes once associated with the Henry H. Weldon Collection, Pat Halfpenny observed differences in the agate striations in the contemporary imposters, which she attributed to possible differences in eighteenth-century versus twentieth-century wheel technology.27 Further research along these lines could identify variability among period factory sites and perhaps individual potters.

For laid agate, although the patterning is often described as random, we have concluded that it is very deliberate. This deliberateness can be seen in a variety of other agate patterns that have yet to be fully classified (figs. 6366). As more information becomes available from the excavation of Staffordshire production sites, perhaps an explicit typology can be developed using the agate “fingerprints” that may be inherent in each example.

A larger issue to discuss is why agateware, although intermittently fashionable within the last three hundred years, has never been made in large quantities compared to other decorative ceramics types. Some ceramics historians have typically characterized agateware as costly and labor intensive in order to explain the relatively small production levels.28 From the consumer side, in contrast, examination of American invoices from the 1770s suggests that agateware was only moderately more expensive than undecorated creamware.29 Even when the Staffordshire potters produced an inexpensive transfer-printed version of agateware in the nineteenth century, the pattern was not popular.

Beyond costs, however, consumer demand for agateware must also be considered. A long-term view of agateware shows peaks of production in between extended periods when more austere ceramic styles were in vogue. In effect, this trend suggests that agateware was more a novelty than a product with staying power. Archaeological evidence helps with this. At John Dwight’s factory few agateware sherds were recovered from the many tons of waster fragments found.30 The recent 1997–1998 excavation at the U.S. Pottery Factory in Bennington only revealed 309 agateware sherds out of the 27,000 ceramic fragments recovered.31 These numbers do not suggest a popular ceramic type.

Archaeological evidence from domestic sites also hints at a low volume of public consumption. Without question, the English thrown agateware of the 1740s and 1750s far outnumber those of laid agates encountered in American sites. Although quantification has yet to be conducted, only a handful of laid agateware is present among the hundreds of thousands of eighteenth-century ceramic fragments excavated in Williamsburg, Virginia. This scarcity has been noted at other American archaeological sites as well.32

Why, then, does laid agateware appear to have survived in relatively large numbers in ceramic collections? Has it always been considered the “holy grail” among ceramics types and thus cherished and protected? How can this dichotomy be explained? Perhaps Josiah Wedgwood can help answer these questions when we look at the second part of his statement written in 1759: “I had already made an imitation of Agat which was esteem’d very beautiful, and a considerable improvement, but the Country had been surfeited with variegated colours.” The Oxford English Dictionary defines surfeit as “to oppress or nauseate with overabundance of something.”33 Wedgwood himself ultimately turned his attention to his extraordinarily plain creamware.

Without question, agateware can generate a kaleidoscopic effect that some may find dizzying. Although the general public has never embraced agateware products, a fierce competition for antique examples exists among a small cadre of collectors—past and present. Perhaps this fact alone substantiates the often heard claim that agateware is considered “the ultimate refinement of the pottery’s art.”34 We hope this demonstration has provided some insight into the mysteries of the potter’s art and that new research on the history of agateware can be conducted with fresh eyes.

Acknowledgments
The authors thank Abe Addonizio, Gavin Ashworth, Bob Barth, Amy Earls, Rodney Hampson, Al Luckenbach, Ivor Noël Hume, George Miller, Frank Russo, and Janine Skerry. We are especially grateful to Troy D. Chappell for his comments and suggestions.