JAIC 1984, Volume 23, Number 2, Article 5 (pp. 130 to 152)
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Journal of the American Institute for Conservation
JAIC 1984, Volume 23, Number 2, Article 5 (pp. 130 to 152)


J. William Shank

ABSTRACT—The painting career of John Singleton Copley (1738–1815) in America and England is outlined. In a technical study of three paintings from his major stylistic periods, pigments are analyzed, and information regarding the artist's materials and sources is provided.


THE STORY OF JOHN SINGLETON COPLEY is one of the earliest examples of The American Dream: a tale of rags-to-riches, achieved through one man's strong motivation, personal initiative, single-mindedness of purpose, and a spark of creative genius. The son of Irish working class immigrants in colonial Boston, Copley elevated himself, almost single-handedly, to a level of social prominence, first in a colonial town where artists were treated as merely useful craftsmen, and later in the sophisticated artistic circles of eighteenth-century London, during the formative years of the Royal Academy.

Born in 1738, Copley spent the first ten years of his life with his widowed mother over the Long Wharf tobacco shop of which she was the proprietress. Mary Copley's re-marriage in 1748 was a fortuitous one for the ten-year-old boy, whose stepfather, Peter Pelham, was an engraver of mezzotints. Through Pelham, Copley gained access not only to the tools and materials of the artist, but also to the small circle of artists then active in New England. He surely knew John Smibert personally and was acquainted with the works of Robert Feke, Joseph Blackburn and John Greenwood. Copley's earliest works include re-workings of his stepfather's engraving plates and sketches from books of anatomical studies, as well as early attempts at oil painting, in the form of plagiarized mythological scenes. But the limner tradition of the painted portrait was, early on, to become his principal preoccupation. Portraiture was not only the most abundant source of existing painting for the young Copley, it was also the most practical choice of subject matter for a youngster hoping for a career in art: it paid.

With the early death of Peter Pelham in 1751, the thirteen-year-old Copley determined to add to the family income with his art. His earliest portraits show the strong influence of his predecessors in their flat shapes, shallow modelling, and sometimes pompous gestures. But almost from the start, his cool, metallic coloring was his own. Rapidly, in the 1750's, Copley moved past the limner artists of the generation before, to produce an illusion of reality in his portraits unprecedented on this side of the Atlantic. If his draftsmanship and his grasp of anatomy were somewhat lacking in his early works, his rendering of textures was unsurpassed; while still a teenager, John Singleton Copley was producing paintings better than any he had ever seen.

Copley's gift, and his own self-promotion, made him much sought-after among the merchant classes of Boston in the late 1750's and 1760's. By 1769 his lucrative practice, which by then included commissions as far away as New York and Philadelphia, enabled him to purchase a 21-acre farm on what is now Beacon Hill. Copley was a fastidious painter, and his demands on his sitters were sometimes excessive: one subject recalled making fifteen return visits to the artist's studio for the usual six-hour sitting.1 His hard labor was rewarded by an increasingly sophisticated style and fluid application of paint. Copley's colonial sitters sit or stand immobile, staring resolutely at the viewer from the foreground picture plane. The familiar household objects or furnishings which surround them are portrayed with the same crisp three-dimensionality, with backgrounds generally minimized through the use of very thin scumbles of paint. His subjects are bathed in a single, direct light, and their strong plasticity is created by the use of strong, deep shadows at the edge of the form, with a very limited use of a middle ground to separate the darker areas from the broader expanses of light color.2 Despite the increasing virtuosity with which Copley rendered fabrics and flesh, the portraits of his mature American style are totally lacking in the “aerial envelope”3 which in optical reality would separate them from the viewer.

It was precisely the crisp, clear directness of Copley's approach to painting which brought his work to the attention of the London Society of Artists when he first submitted a picture (the Boy and a Squirrel of the Museum of Fine Arts, Boston) for its approval in 1766. Despite the encouragement of such luminaries as Benjamin West and Sir Joshua Reynolds, eight years and the beginning of a Revolution were to pass before the American artist could bring himself to sacrifice his thriving Boston practice in order to pursue a daydream of success in the London art world, as well as to risk meeting the challenge of breaking away from the restrictions of portraiture by trying his hand at history painting.

His move to England was long premeditated. As early as 1767, he complained that in America, painting was regarded as merely “a usefull trade … like that of a Carpenter, tailor or shewmaker, not as one of the most Noble Arts in the world.”4 He had become dissatisfied with “preserv(ing) the resemblance of perticular persons,”5 and understandably so: by the age of 36, at which time he left the colonies, Copley had painted more than two hundred portraits. A man with seemingly no political leanings of his own, Copley painted revolutionaries (e.g. Paul Revere) and loyalists (his father-in-law Richard Clarke, who was consignee for the tea of the Boston Tea Party) alike. “Art and politics do not mix,” he wrote6; indeed, his bipartisanship might have cost him dearly had he stayed in America past 1774. One critic attributes his move to England to an avoidance of having to choose between the Tories and Whigs, thus losing half his clientele.7

The move was certainly a professional, not a political, one. Before settling in England, he toured the Continent, immersing himself especially in the art of the High Renaissance, and discovering a particular affinity for Titian. The differences between his own work and that of Titian impressed him more deeply than the similarities; Copley began to consider the question of atmosphere and how to achieve it, from a technical aspect. His letters home to his artist half-brother, Henry Pelham, are full of hypotheses about the materials of the Venetian masters.8

From the time of his settling in London in 1775, John Singleton Copley was a force to be reckoned with. His eventual success with grand-scale history paintings (e.g. Watson and the Shark, 1778; The Death of Chatham, 1781; The Siege of Gibraltar, 1787) swelled his already considerable ego, along with his reputation. The portraiture still continued, although the sitters were now lower nobility, landed gentry, and members of the military. His sometimes extravagant multi-figural compositions and the bravura brushwork of his English works were clearly influenced by the Grand Manner pictures then in favor among the other members of the Royal Academy (Copley became a Royal Academician in 1779). The sober poses and often subdued palette of his American works gave way to fanciful postures and a vibrant, higher-key range of colors. Remarkably enough, notes Prown,9 despite these changes in style, the manner of application of paint to canvas remained much the same. “He was still laying out his pictures area by area, as in his colonial works. The color areas remain distinct, creating a pattern of their own on the surface, and do not fuse into one another to create a unified, homogenous picture.”

Copley's English career included flirtations with royal commissions, public showings of his large-scale history paintings, and major political conflicts with other members of the Royal Academy, most notably Benjamin West. The painter from the colonies seemed to carry with him the defensive self-righteousness of the outsider, a flaw which brought him into frequent conflict with his peers and may have somewhat stunted his career. Toward the turn of the century, Copley also began to find his works increasingly out of favor for their “rococo flamboyance … in a period of classical restraint and simplicity.”10 But he continued to produce paintings of extraordinary quality, including over 250 group and individual portraits, during his English period. Before his gradual decline in the early years of the nineteenth century, John Singleton Copley proved himself as a viable force in the world of European art, as well as the first artist of international stature to have been wholly trained in the New World.


(For instrumentation and procedures, please refer to the Appendix.)

3 EARLY AMERICAN WORKS (ca. 1753–1760)

PICTURE PAINTERS IN COLONIAL America were, by and large, dependent upon the Old World as a source of artists' materials. An article11 by P. England and L. van Zelst of the Museum of Fine Arts in Boston investigates the pigments used by artists in seventeenth-century New England, i.e. in the period between fifty and one-hundred years before Copley's time. Their findings indicate that the materials present in colonial American paintings at that time correspond closely to those then in common usage in Europe, from the warmly colored grounds to a variety of colorful, professionally manufactured pigments.12

A 1720 advertisement, cited in the aforementioned article,13 promotes paints from London available for purchase at the dock in Boston. Copley's stepfather, Peter Pelham, and his circle of artist-friends had steady access to art suppliers abroad: connections that were most likely communicated to the young painter. By the time Copley's career in America had begun to flourish, shops for artists' supplies existed in New England itself; a letter written home to Henry Pelham in Boston during Copley's travels in Italy (Parma, 25 June 1775)14 mentions, “… Colours ground in oyl, as you get them from the Colour shop.”

3.1 DOROTHY MURRAY (ca. 1760)

The painting from Copley's earliest period chosen for study is a portrait of Dorothy Murray (later Mrs. John Forbes, 1745–1811), now in the collection of the Fogg Art Museum (1929.321). The sitter, daughter of a Boston merchant class family, is presented with her dark hair swept back, her throat encircled by a pearl necklace, and her arms haloed by billows of lace; she stares steadfastly at the viewer in three-quarter profile. A wreath of colorful flowers is held loosely in her hands. Broad expanses of light flesh tones make the solidity of Dorothy's form stand out from the dark brown background, and a single light source casts strong shadows across her flesh. The anatomical uncertainties, most evident in the treatment of the sitter's arms and hands, are typical of Copley's youthful works (Fig. 1).

Fig. 1. Dorothy Murray, Fogg Art Museum (photo: Fogg Photo-Services Dept.).

3.1.1 SUPPORT:

The canvas support for the painting, which has been lined at least once (the present lining adhesive appears to be glue or paste) is linen, of plain weave, with about thirteen threads, of very irregular widths, per centimeter. The nature of the canvas is clearly visible in the x-radiograph (and easily distinguished from the lining canvas) because of the presence of a lead-containing ground layer which fills the interstices of the fabric.

3.1.2 GROUND:

The whitish ground layer contains both lead white and calcite, in proportions of approximately three-to-one. It is thinly and evenly applied and does not obscure the texture of the support. There is no evidence of an underdrawing.


The painted design is handled directly and simply, with overlapping of layers confined to the depiction of materials which are layered in reality (e.g. the transparent lace sleeve over the flesh of the sitter's arm; and the embroidered decoration of the dress bodice). Some glazing is in evidence in the dark shadows of the dress. The general layout of the paint layer is a side-by-side application of lights and darks which are blended into each other, probably while wet. An obvious effort was made by the twenty-one-year-old artist to disguise the brushwork, and very little impasto is present.

BINDING MEDIUM: While no analysis of the painting medium was conducted, the painting appears to be executed in a traditional oil medium. Copley's writings frequently mention both “nut oil” and poppy oil.15 A rare reference to “Linseed Oyl” refers to its use for house-painting.16

PIGMENTS: Pigments found to be present in the portrait of Dorothy Murray include lead white, calcite cinnabar, vermilion, yellow ochre, orpiment, Prussian blue, and charcoal black. Organic red and yellow stains were also observed. (For specifications of pigment analyses and results, please refer to Table 1.)

Table 1 DOROTHY MURRAY, Fogg Art Museum, 1929.321 36�″ (h) � 28″ (w); 91 cm (h) � 71 cm (w)

4 MATURE AMERICAN WORKS (ca. 1761–1774)

COPLEY'S MATERIALS DURING this successful period in his career came, at least in part, from England. An order for supplies, dated 6 June 1771,17 (and a corresponding in voice, dated 17 August 1771)18 from Henry and Thomas Bromfield, London, includes the following items, among others: poppy oil, brushes, bladders (presumably for paint storage), and “hog hair tools of the smallest size for portraits.”


The portrait of Nicholas Boylston (1716–1771) in the collection of Harvard University (H-90) represents Copley at the peak of his career in America. Executed in 1767, it is one of three portraits of the same sitter in the identical pose. Boylston, a Boston merchant, is shown in an informal dressing gown and without a powdered wig: his shaved head is partially covered by a stylish turban (Fig. 2).

Fig. 2. Nicholas Boylston, Harvard University Portrait Collection (photo: Fogg Photo-Services Dept.).

A quantum leap in the sophistication of painting style between this portrait and that of Dorothy Murray, dated only eight years earlier, is immediately apparent. Both the flesh and the draperies are treated with a startling realism. The lush darkness of the shadows and the brilliance of the light tones combine to create intensely volumetric forms without the intrusion of “atmosphere” between the sitter and the viewer. Only the background seascape is loosely, and lightly, painted, creating the illusion of distance between the two single planes of the painting.


While the Nicholas Boylston portrait has been mounted on a solid aluminum support, and no information is available regarding its original attachment to an auxiliary support, another painting of the same period yields further information about Copley's stretchers. A portrait of John Murray, of about 1763, was treated at the Center for Conservation and Technical Studies by painting conservator Elizabeth Jones19 in 1967. The painting, which had never been lined, was attached, with hand-wrought nails, to a wooden strainer of the tongue-in-groove, butt-end type, with its corners held fast by wooden dowels (Fig. 3).

Fig. 3. Detail of strainer from Copley's John Murray, courtesy of the Center for Conservation and Technical Studies, Fogg Art Museum (photo: Will Shank).


The linen canvas of the Boylston portrait is of an uneven weave (plain type), with about fourteen threads per centimeter. The white ground layer is thinly applied, allowing the texture of the support to show through. (Copley evidently was in the habit of smoothing his ground layer or layers with pumice: see his letter to Henry Pelham, 14 March 1775.20) X-ray diffraction analysis proves its composition to be mostly calcite, with some lead white. Analysis of the aforementioned John Murray portrait (New Brunswick Museum, St. John, New Brunswick) shows that the ground layer extended to the margins of the original tacking edges, indicating the strong likelihood that the canvases were pre-primed.21 X-ray diffraction analysis of the John Murray ground reveals a composition similar to that of Nicholas Boylston.

While the following list does not indicate whether or not the canvases were pre-primed, or even pre-stretched, it does make clear that Copley ordered his canvases pre-cut from London merchants during his heyday in America. The following is a partial invoice of materials from “Henry and Thos. Bromfield in the Thames, London,” dated 17 August 1771:22

  • 6 fine half length Cloths
  • 6 d.� Kit-Cats
  • 6 d.� Three Quarters
  • 6 d.� fine ticking half Lengths
  • 6 d.� three Quarters

(Note: Ralph Mayer's Dictionary of Art Terms & Techniques, New York, Thomas Y. Crowell Co., 1969, states that the following were standard dimensions for portrait-size paintings in England and America: kit-cat, 28″ � 36″; half length, 40″ � 50″; and three-quarters, 25″ � 30″.)

The above invoice also includes references to both “3 oz. Italian white chalk” and to “a keg of grod. (i.e. ground) white lead”.23 These materials correspond to the findings of the technical analysis of the ground layers of both paintings from this period.


Despite the stylistic advances which separate Nicholas Boylston from Copley's works of the 1750's, his technique is remarkably the same. Cross-section analysis of one of the areas most likely to be a glaze, the darker green pattern of the sitter's dressing gown, clearly shows a single layer of blue-green paint over the white ground. The cross-section taken from the background seascape shows a similarly simple layering of ground and paint. Light and dark areas of flesh and draperies are laid in side-by-side rather than one above the other. Layering is limited to obvious areas, such as the yellow title over the red book cover under the sitter's proper left arm.

BINDING MEDIUM: The medium appears to be traditional oil, most probably poppy or walnut oil.

PIGMENTS: Among the pigments found, or estimated, to be present in the Nicholas Boylston portrait were the following: lead white, calcite, vermilion, Prussian blue, (indigo?), and charcoal black. Organic reds, yellows, and browns were also used. (Please see Table 2 for further information.)

Table 2 NICHOLAS BOYLSTON, Harvard University, H90 50″ (h) � 40″ (w); 127 cm (h) � 102 cm (w)


While it is impossible, from the present state of any of the paintings at hand, to judge the nature of Copley's original surface coatings, which have long since been removed and replaced, some clues are left behind in contemporary writings regarding his varnishes. While still travelling in Italy in 1775, Copley writes home to his half-brother, “My spirit varnish is unknown to them (i.e. the English painters).”24 The varnish referred to is probably the same one described in a letter from Copley to an artist friend, Ozias Humphry, which was later recorded in Humphry's memo book as “Mr. Copelys Varnish.”25 It reads as follows:

  • A pint of spirits of rectified wine
  • � of a pd of gum sandrack
  • 4 spoonfulls of Canada Balsam (Copley calls it Balsam of Fir)
  • put these together in a Bottle & place them either
  • in a Summer sun or near the fire remembering that the
  • Bottle must not be stop'd close as it wd certainly burst.

5 ENGLISH WORKS (after 1774)

WHEN COPLEY LEFT AMERICA in 1774 to begin the Grand Tour of the continent and eventually to settle in London, a whole new world of art opened up to him. In Italy, before the works of the great masters of the Renaissance, the American artist began to ponder questions that he had never considered before, regarding the possibilities of applying paint to canvas.

He was particularly struck by the basic differences in appearance between his own works and those of Titian, and he questioned the techniques that came to make them look as they did. Copley speculates on the preparation of Titian's canvases in this letter from Rome, dated 14 March 1775:

He seems to have had his Cloath first Passed over (with Whiting, White Lead, or Plaster of Paris, mixed with sise) with a Brush, and no other preparation or Priming; perhaps not even pumissed: only the Cloath pretty even thread and fine.26

Titian's medium, too, impressed Copley as something quite dissimilar to the pigments ground in oil to which he was accustomed.

… I am inclined to think Plain oyl Colours will not produce the effect of Titianos Colouring. there is somthing too Dauby in it.27

He suggests experiments to Henry Pelham to simulate Titian's layered paintings:

I will tell you what I propose; first to prepare my Cloath as above, than Dead Colour my Picture. the Ground will imbibe the Oyl. When it is Dry Pass over it with some Gum Mastick Dissolved in Turpentine, which I shall let Dry, than finish my Picture with Glasing boath in the lights and shades. The Gum is to prevent the Dead Colour imbibeing the Oyle, so it will appear through the last Glasings with great Brilliancy. another method I shall try is to lay in the Dead colours with Turpintine and than apply the Gum before the finishing: which should be by Glasings only. but when I have made the experiment I shall let you know its success.28

The concept of glazing to create form and colour was one quite alien to Copley, whose paints were applied in so straightforward a manner. He marvels at Titian's Venus of Urbino in a letter from Parma, 25 June 1775:

… many of his shades are given only by the glaizeings. for instance the thighs of his Venus were laid in without the divition between them being marked. and when he came to glaize, he has run over with a tint through which you see the flesh and marked the divition this way.29

He advises his half-brother to reconsider the use of undiluted oil colors, in the same letter:

I recommend to you to take some spirits of Turpentine and mix up a flesh tint and put it on a peace of linen cloath; than mix another with oyl of Poppy or nuts, and put that on the linen by the side of the other, and you will see a briliancy and Strength in that mixt with turpentine, and the other will look Dark, cold and greasy. the same differance you find between those tints, you find between the Pictures of Titian and those of other masters.30

and to try the following procedure for executing a Titianesque picture:

Take a good Cloath, pass over it with Spanish'd White mix'd with size, so rubed into the Cloath that all the pores are filled. let it dry. than with your pencil (i.e. paintbrush) draw your outline with Dark colour. this done, set your Pallet with Colours ground in oyl, as you get them from the Colour shop. They will be very stiff. dilute them with spirits of Turpentine, and pint your Picture with a good body in the lights and very thin in the shades, and in this way bring your Picture to as great a degree of perfection as you can. when you can do no more, pass over your Picture (which will be intirely sunk in) with mastick Varnish. let is dry and your picture will appear very brilliant, and have an even gloss. this done, take retouching Varnish and anoint the picture, not all over at onee but by peace meal, for instance an head, hand, etc., or what ever you mean to improve, and finish your Picture by glaizeings with Colours first ground in oyl and than diluted with the retouching varnish, and if necessary add a little oyl. by glaizeings I mean not only glaizeings in the Shadows, but Scumbling all over the lights with Virgin tints … your Picture, when dry, Varnish with Mastick Varnish, or Spirit Varnish if it will bear it; but I should think without trying it, it would tear up the Colours.31

Copley's initial fascination with the technique of the old masters seems to have remained, in large part, theoretical. Prown suggests,“ … although he planned to experiment with this (in reference to above letter from Parma), he did not plan to spend much time trying to imitate another painter, especially since Reynolds, West and others had wisely told him it would be a mistake to alter his style.”32

Ironically, it was the style of these same English artists which would have the most marked effect upon Copley's work after he settled in London in 1775. They proved, in some instances, to be poor examples for Copley, in terms of experimentation with untested painting materials and techniques.

As preparation for his English paintings, which often involved complex multifigural compositions, Copley learned to sketch from life: he writes to Henry Pelham from Paris, 2 September 1774:

let me recommend to you to keep the faces of your portraits, perticularly your Weomens, as Clear of Shade as possable, and make broad Masses of Lights and shade. practice continually. Draw Landscapes, Dogs, Cats, Cows, horses, in short I would have you keep in your Pocket a book and Porto Crayon—as I now do—and where ever you see a butifull form Sketch it in your Book.33

A method of transferring sketches to canvas became necessary; this description is of Copley's approach to the creation of the Ascension of 1775:

… I sketched my figures, keeping the greatest simplicity with a great breadth of Light and shadow…I traced them on the Paper on which my Drawing was to appear to the Publick, just in the way you have seen me proceed with Draperys, etc., in my portraits. when I had got all my out line correct and clean, for I had traced it all from other sketchs, I began to wash in the shades with bister.34

While no actual underdrawings appear in any of the portraits in this study, another painting in the Fogg's collection shows Copley's layout of a facial composition with warm, thinly applied outlines, probably of the bistre he mentions above. The sketch of Major General August de la Motte, painted in 1787 for The Siege of Gibraltar, shows that a very linear treatment of the basic composition exists under the fully modelled forms (Fig. 4).

Fig. 4. Major General August de la Motte, Fogg Art Museum (photo: Will Shank).

The undesirable elements that crept into the physical make-up of Copley's pictures in England were most likely inspired by the technique of Benjamin West and Joshua Reynolds, the latter a notorious experimenter with painting materials. Copley notes:

Mr. Wests Receipt for retouching Varnish … is as follows: Take about one Ounce of Gum Mastick, Dissolve it in Spirits of Turpentine, and while it is warm add about a Table spoonfull of Nut or Poppy Oyl, and add about half a Table spoonfull of Spermicity to break the texture of the Gum. this you apply to your Picture with a brush. it will never change or leave any stain.35

A similar mixture could be used as a “method to give richness to your Colours.”36

A contemporary biographer of Reynolds, Marchi, notes that the artist used megilp (a mixture of mastic resin, turpentine and linseed oil, similar to the one described above) to serve as a tint. It often yellowed and had to be removed within months of its application.37 Reynolds was also known to mix incompatible pigments such as orpiment and lead white, and to use fugitive colors such as lakes and carmines.38 Other additives such as driers and wax were mixed with oil paints, and several media were “wrecklessly superimposed.”39

Copley's English works show signs of similar inclusions in the paint layer. A portrait of John Adams, painted in 1783 (and now in the Harvard University Portrait collection), examined and treated by the author in 1983, showed the characteristic signs of bitumen or other resinous inclusions in the paint layer.


The portrait of Mrs. Rogers (born Abigail Bromfield; she was the artist's stepniece) is a fine example of Copley's portrait style in the 1780's (Fig. 5). The vibrant depiction of a young woman in a satin gown and feathered hat is alive with motion around the calm stare of the sitter. Copley's brushwork is lively and spontaneous. The probability that the artist had picked up a great deal of speed in his work is evidenced by the “halo” effect around, for instance, the hat ribbons where they meet the sky. Copley did not take the time to carefully fill in the gaps between the colors. Pentimenti are also in evidence.

Fig. 5. Mrs. Daniel Denison Rogers, Fogg Art Museum (photo: Fogg Photo-Services Dept.).

5.1.1 SUPPORT:

The original canvas is linen of a fairly fine, if irregular, plain weave, with about fifteen threads per centimeter.

5.1.2 GROUND:

The ground layer clearly contains lead, judging from the appearance of the canvas in the x-radiograph. Examination with both the polarizing microscope and the scanning electron microscope confirms the presence of lead white, along with calcite.


Cross-section analysis brings to light some interesting structural features of Mrs. Rogers. A sample taken from the orange sunset shows a layer of light blue/green underpainting beneath the surface color, the same color, apparently, which shows through at the juncture of the hat ribbons and the sky. A cross-section taken from a white highlight on the tree trunk behind Mrs. Rogers reveals an unusually complex structure of layering of paint. The white highlight is painted over the brown of the tree, the blue/green underpainting, and the white ground. Above the white highlight is a dark brown resinous glaze (perhaps bitumen) which has been used as a “softening” or atmospheric effect on this formal background element, evidently so that the highlight would not appear too bright.

Whether or not Copley mixed meglip or other resinous elements with the paints of this portrait remains a question. It should be noted, however, that ultraviolet fluorescence reveals a surprisingly extensive pattern of wide craquelure (since inpainted) quite foreign to Copley's American works like Nicholas Boylston.

BINDING MEDIUM: The medium appears to be traditional oil, probably poppy or walnut oil, apparently medium-rich.

PIGMENTS: The palette employed by Copley in this English portrait seems to be virtually identical to the one he used in America. Pigments identified, or estimated to be present, in the portrait of Mrs. Rogers include: lead white, calcite, vermilion, (hematite/red ochre?), Naples yellow/yellow ochre, charcoal black. Unidentified red, yellow, and blue stains were also observed. (Please see Table 3.)

Table 3 MRS. DANIEL DENISON ROGERS, Fogg Art Museum, 1979.179 50⅛″ (h) � 40″ (w); 127 cm (h) � 102 cm (w)


While the paintings of John Singleton Copley experienced wide stylistic swings between the time of Dorothy Murray and that of Mrs. Rogers, the physical make-up of his works seems to have changed very little indeed. This consistency is due in part to the fact that while still in colonial America, Copley was already using “colourmen” in London, where he would eventually live and work. His palette varies hardly at all between his American and his English works.

What is surprising in the Copley story is the fact that an artist of such tremendous ego, who tended to treat his peers with condescension if not outright contempt, should adapt his painting style at all toward that of his English contemporaries, as he seems to have done to some limited degree. The complexity of structure identifiable in Copley's later works remains, however, only an embellishment to the straightforward, direct manner with which the American-born artist had always applied paint to canvas.


I am grateful to the administration of the Fogg Art Museum for allowing me to carry out technical analysis on the portraits of Dorothy Murray and Mrs. Daniel Denison Rogers. I am especially thankful to Louise Ambler, curator of the Harvard University Portrait Collection, for making Nicholas Boylston available for study.

I should like to thank also Ann Hoenigswald at the National Gallery of Art, Rosamund Westmoreland, formerly of the National Portrait Gallery, Betty Jones, private conservator of painting in Connecticut, and, at the Museum of Fine Arts in Boston, Trevor Fairbrother of the paintings department, as well as the paintings conservation staff, especially Brigitte Smith. At the Fogg, thanks are due to Arthur Beale, Kate Olivier, Teri Hensick, and especially to Gene Farrell and Richard Newman for their invaluable help in the analytical laboratory.

I am indebted to the National Museum Act, whose support made my internship at the Fogg possible.





Paintings were examined and sampling was done under a Zeiss 50 stereobinocular microscope equipped with a fiberoptic illuminator at 15.6x magnification. Care was taken to avoid sampling areas of the paintings which included later restorations.


Samples of pigments, grounds and canvas fibers were mounted on microscope slides with cover glass in Aroclor 5442, a standard mounting medium with a refractive index of 1.66. They were examined under transmitted light on a polarizing microscope, Leitz Laborlux -12, at magnifications ranging from 50x to 1000x.

Cross sections were examined under the same microscope in reflected light at 50x to 200x magnification. The sections were mounted in Buehler Epo-kwik resin, which was allowed to harden, then cut, sanded, and smoothed.


Pigment samples were subjected to microchemical testing under an Olympus polarizing microscope at 100x magnification.


X-radiographs of all paintings were taken with a Baltospot industrial unit which operates at 5 milliamps and is adjustable up to 100 kilovolts. Settings used varied from 40 kv for 50 seconds (for the paintings lined to canvas) to 40 kv for 90 seconds (for the painting mounted on aluminum). Film used was Dupont Cronex NDT 55 Industrial, in 14 � 17-inch “day packs.”


Paintings were examined with a Dage 800 modified television camera with a Hammamatsu N214 vidicon tube, connected to a high-resolution Conrac television monitor. A quartz halogen light source was used for illumination.


Samples were mounted on glass rods with collodion. They were x-rayed with a Diano 8000 XRD equipped with a Gandolfi cylindrical camera (114.6mm internal diameter). It is equipped with a Cu target (1.5404 A) and a Ni filter. The samples were run at 35 kv, 10 milliamps, for approximately 17 hours. The x-ray patterns were identified by comparison with published standard (Joint Committee on Powder Diffraction Standards, Swarthmore, Pennsylvania).

1.1.7 SCANNING ELECTRON MICROSCOPY (with energy dispersive x-ray analysis):

Samples were mounted, under the Zeiss binocular microscope, in collodion on a Buehler epoxy resin block, and examined at up to 5000x magnification with a Coates and Welter Cwik-Scan 100, equipped with a Kevex energy dispersive detector for x-ray emission analysis.


Paintings were examined with an ultraviolet mercury lamp of 118 volts and 100 wattage with a peak of 3600 angstroms.


DarrellSewell, Copley from Boston (catalog). Boston: Museum of Fine Arts, 1980, no pp.

Martha BabcockAmory, The Domestic and Artistic Life of John Singleton Copley. Boston: Houghton-Mifflin, 1882, p. 36.

VirgilBarker, “John Singleton Copley,” in Four Boston Masters (catalog). Wellesley: Jewell Arts Center, 1959, p. 22.

John SingletonCopley, et al, Letters and Papers of John Singleton Copley and Henry Pelham, 1739–1776. New York: Kennedy Graphics, 1970, p. 66.

Letters and Papers of John Singleton Copley and Henry Pelham, 1739–1776. New York: Kennedy Graphics, p. 65.

Jules DavidPrown, John Singleton Copley (catalog: National Gallery of Art). New York: October House, 1965, p. 70.

John Singleton Copley (catalog: National Gallery of Art). New York: October House, p. 70.

Copley, op. cit., pp. 333–344.

Jules DavidPrown, John Singleton Copley. Cambridge: Harvard University Press, 1966, p. 314.

Ibid., p. 316.

P.England and LvanZelst, “A Technical Investigation of Some Seventeenth Century New England Portrait Paintings,” A.I.C. Preprints, Milwaukee, 1982

Ibid., p. 89.

Ibid., p. 91.

Copley, op. cit., p. 334.

Ibid., p. 115.

Ibid., pp. 172–3.

Ibid., p. 115.

Ibid., p. 140.

Information from the files of the Center for Conservation and Technical Studies, Fogg Art Museum, Harvard University, and from a telephone conversation with Elizabeth Jones, March 1983.

Copley, op. cit., p. 306.

See reference #19.

Copley, op. cit., p. 140.


Ibid., p. 337.

Prown, op. cit., p. 254: quotes the Humphry memo in footnote #28, from British Museum add. ms. 22949.

Copley, op. cit., p. 306.

Ibid., p. 307.


Ibid., p. 335.

Ibid., p. 334.


Prown, op. cit., p. 254.

Copley, op. cit., p. 244.

Ibid., pp. 297–8.

Ibid., p. 336.

Ibid., p. 337.

WaldemarJanuszczak, ed., Techniques of the World's Great Painters. Oxford: Phaidon Press Ltd., 1980, p. 68.

Ibid., p.66.



Copley, John Singleton, et al, Letters and Papers of John Singleton Copley and Henry Pelham, 1739–1776. New York: Kennedy Graphics, 1970.

Reynolds, Sir Joshua, Discourses, ed.EdmundGoss. London: K. Paul, Trench and Co., 1884.

Amory, Martha Babcock, The Domestic and Artistic Life of John Singleton Copley. Boston: Houghton Mifflin, 1882.

Anon., American Portraits by John Singleton Copley (catalog). New York: Hirschl and Adler Gallery, 1975.

Anon., John Singleton Copley, 1737–1815 (catalog). Boston: Museum of Fine Arts, 1938.

Barker, Virgil, “John Singleton Copley,” in Four Boston Masters: Copley, Allston, Prendergast, Bloom (catalog). Wellesley: Jewett Arts Center, 1959.

Belknap, Waldron Phoenix, Jr.American Colonial PaintingCambridge: 1959.

England, P.A., and L.vanZelst, “A Technical Investigation of Some Seventeenth Century New England Portrait Paintings,” A.I.C. Preprints. Milwaukee: 1982.

Fairbanks, Jonathan L., John Singleton Copley, Gilbert Stuart, Benjamin West in America and England (catalog). Boston: Museum of Fine Arts, 1976.

Fairbanks, Jonathan L., and Robert F.Trent, New England Begins: The Seventeenth Century (catalog). Boston: Museum of Fine Arts, 1982.

Fairbrother, Trevor J., “John Singleton Copley's Use of British Mezzotints for his American Portraits: A Reappraisal Prompted by New Discoveries,” Arts Magazine, Vol. 55, No. 7, March 1981, pp. 122–130

Flexner, James Thomas, America's Old Masters. Garden City: Doubleday, 1980.

Flexner, James Thomas, John Singleton Copley. Boston: Houghton Mifflin, 1948.

Frankenstein, Alfred Victor, The World of Copley. New York: Time-Life, Inc., 1970.

Gettens, Rutherford J., and George L.Stout, Painting Materials: A Short Encyclopaedia. New York: Van Nostrand Co., Inc., 1942.

Gettens, Rutherford J., and George L.Stout, “The Stage Microscope in the Routine Examination of Paintings,” Technical Studies, Vol. IV, No. 4, April 1936, pp. 207–233.

Harley, R.D., Artists' Pigments, c. 1600–1835. London: Butterworth & Co., 1970.

Januszczak, Waldemar, ed., Techniques of the World's Great Painters. Oxford: Phaidon Press, Ltd., 1980.

Morgan, John Hill, John Singleton Copley. Windham, Connecticut: Walpole Society, 1939.

Morgan, John Hill, “Some Notes on John Singleton Copley,” reprinted from The Magazine Antiques, March 1937.

Parker, Barbara Neville, John Singleton Copley: American Portraits in Oil, Pastel and Miniature (catalog). Boston: Museum of Fine Arts, 1938.

Plesters, Joyce, “Cross-Sections and Chemical Analysis of Paint Samples,” Studies in Conservation, Vol. II, No. 3, April 1956, pp. 110–155.

Prown, Jules David, John Singleton Copley. Cambridge: Harvard University Press, 1966.

Sewell, Darrell, Copley from Boston (catalog). Boston: Museum of Fine Arts, 1980.

Wehle, Harry B., An Exhibition of Paintings by John Singleton Copley (catalog). New York: Metropolitan Museum of Art, 1936.

Section Index

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