HISTORIC WALLPAPER TECHNOLOGY (continued)
STENCILED AND PRINTED PAPERS
Ordinarily, in analyzing the wallpaper, a restorationist will be called upon to distinguish among the various methods of mass-producing pattern, that is: (1) stenciling, (2) block printing, (3) machine printing, introduced in the 19th century, and (4) silk-screen printing, which became common after the Second World War.
Early 18th-century wallpaper makers in France produced pattern outlines from woodblocks using black ink. The black ink was thin bodied, unlike the thick distemper colors of most 18th- and 19th-century wallpapers. In early examples, the black printed outlines were filled in freehand, or with the aid of stencils, in thin, transparent water colors. This stenciling can be recognized by the presence of multidirectional brush strokes, ending abruptly at the edges of solid-colored pattern shapes, where outlines of color often collected and streaked. Stenciling appears in cheaper wallpaper of the mid to late 18th and early 19th century, but was not a common feature of wallpapers of the best quality.
The use of woodblocks with the printing surfaces carved in relief has been standard in making fine wallpapers. A separate block is required for printing each color. During the mid-18th century, a tradition of fine craftsmanship in this skilled work developed in France and survives today in spite of the development of many alternative methods for mass producing wallpaper.
Distemper colors were normally used for color printing from woodblocks. To make distemper colors, pigments were mixed with water and glue size to produce the thick-bodied, opaque, chalky colors still favored in fine wallpapers. Occasionally, oil-based mediums were used to produce glossy accent colors, but sometimes they were also used for ground colors.
Naturally occurring organic and inorganic pigments were used to make the distemper colors of the 18th century. A list of the standard colors "proper to be used for paper hangings" was published in London in 1758 by Robert Dossie in his Handmaid to the Arts. Dossie's list of colors includes archaic words and color names that are fully analyzed by Rosamond D. Harley in Artist's Pigments ca. 1600-1835 (New York: American Elsevier Publishing Company, 1970). Dossie's list and Harley's study of early color nomenclature and history should be consulted by any researcher undertaking chemical analysis of the pigments present in old wallpapers.
In dating papers, chemical analysis of wallpaper colors may be helpful. The presence of some of the "new" colors discovered and developed in the late 18th and early 19th century may be evidence for the earliest possible date that a wallpaper could have been made. For example, the presence of Chrome Yellow (PbCrO4) indicates a date after 1809. Chrome Yellow was discovered in 1797, but the formula was not published until 1809, and not widely available until after 1820. By mid-19th century, it was used by many wallpaper makers. Sheele's Green-Copper Arsenite is another new color commonly used in the wallpaper trade after its discovery in 1775. Another, Schweinfurt Green-Copper Aceto Arsenite was first produced commercially in Schweinfurt in 1814; the first publication of a method for making the color followed in 1822. A still later color, "Artificial Ultramarine" was discovered in 1826, but its formula was not published until 1828, and the earliest known mention of its use in the wallpaper business was in the year 1864.
In the standard 18th-century wallpaper manufactory, thick distempers were used both for "grounds" and for printing the patterns (figures 4 and 5). After the individual sheets of paper had been "joined"pasted togetherto form a roll of hanging paper, a coating of coloring or of white was applied with wide brushes. This ground color concealed both the joints and any discoloration in the paper stock itself. Multidirectional brush strokes applied by hand are often apparent in the grounds of early papers. Grounding was one of the first processes in wallpaper making to be mechanized. Machines for rotating long cylindrical brushes that applied an even coating of ground color were introduced to the trade by the early 19th century. The uniformity of vertical streaking is sometimes apparent in grounds applied by this mechanical process.
Once the ground coat had dried, the pattern could be printed. The craftsman pressed his block (figure 3; figure 4 just left of center; figure 5, center) against a pad, which had been coated with a layer of the liquid distemper color. Then he lifted his block and let it strike the paper, sometimes tapping it with a mallet to make a firm impression. It was almost like marking a letter with a rubber stamp. The block met the paper in a straight up and down motion. Close examination of the coloring in pattern elements that have been block printed will reveal multidirectional "veining" within pattern shapes that have sharply defined outlines. The veining will often take the form of little sunbursts, formed as the block came down, pressing the color out in all directions. Also visible in the areas of solid coloring may be little holes from the bubbles created during the moment of pressure and release of the block (figure 6A).
In the 1820's, as textile printing was being mechanized using engraved copper cylinders, experiments were made for incorporating this technology in the printing of wallpaper. The Zuber Factory in Alsace produced papers in this manner using thin-bodied, glossy coloring. But the resulting patterns were composed of thin lines, similar in character to engravings, and the venture was of limited commercial significance. Evidence of their use in the United States has not yet been found.
In the 1840's a significant commercial impact of machines on wallpaper printing occurred (figure 8). Steam-powered machines were developed with efficient systems for feeding color to cylinders that printed from raised, rather than engraved surfaces, employing the conventional principle of the woodblock. The standard cylinder had a wooden core with the raised printing surfaces, formed by strips of brass which were tapped into the wood core and made cloisonne-like raised outlines of shapes. Inside of these little walls, felt was tightly stuffed to carry the colors for the solid areas of patterning (figure 9). Details such as lines and dots were printed by appropriately shaped brass pieces. The cylinders were placed on a machine that had at its core a large revolving drum, or giant cylinder, upon which the blank paper rode while it engaged in sequence a series of the smaller cylinders, each of which had a raised surface to print one color of the pattern. Each printing cylinder was coated with its individual coloring by a roller fed belt from a trough that held the appropriate color.
Old papers that bear the impression of these raised-surface cylinders of machine printing can not safely be dated before 1841. The little metal outlines filled with felt left a distinct impression: an outline of thicker coloring around the edges of each shape combined with traces in colored areas of the unidirectional streaking caused by the constantly rotating cylinders (figure 10 and 10A). The colors used on the machines were thin bodied for quick drying. These characteristics of ma chine printing are particularly easy to recognize in cheaper papers.
Silk screens are sophisticated stencils carried on very finely woven silk textile screens, stretched over wooden frames. Patterns produced from these screens can often be recognized with the aid of magnification. The crisscrossing of the woven threads of the textile leave their mark, especially along curves and diagonals. The fact that the coloring material has passed through a woven fabric is indicated by minute little "stair steps" that form the edges of shapes. Silk-screened wallpapers, which have become particularly popular for the more fashionable and expensive patterns produced since the 1940's are often marketed as "hand prints."
Flocking and Metallic Colors
Wool and silk flocking were added to many 18th-century papers. From the 17th century to the present, chopped colored shavings of silk or wool have been spread over areas of patterning printed (or stenciled) in adhesive varnish on wallpaper (figure 7). Occasionally, powdered mica or isin glass was added to 18th-century papers, and in the late 19th century, became very popular wallpaper decorations. Metallic colors, gold and silver, are found in papers of the 18th century, as well as in later wallpapers. Because their use was so long lived, the presence of any of these textured decorations does not in itself provide a basis for dating a paper.
The development of the methods by which wallpapers were fixed to the wall provide further dating guidelines. During the early 18th century, the English used tacks to hang wallpapers and evidence for this practice in America has been found as early as 1741.2
The tacks used along the edges of paper were covered with borders, which were also tacked to the walls. English instructions of 1700 for tacking up wallpaper include the advice that the back side of the paper first be gently wetted to make it hang smoothly.
Early 18th-century wallpapers were sometimes pasted sheet by sheet to the wall. American references indicate that papers were sometimes fixed to fabrics and canvas before they were hung. But by the mid-18th century, papers were more commonly bought in rolls, and pasted directly to the walls. An invoice of paper hangings shipped in 1799 from London to Virginia was accompanied by a note: "The process of putting up paper hangings is to have the wall as smooth as possible and then to be well sized over. The ingredients used for making of paste is flour and water with a small quantity of Allum put in and boiled till quite thick." Although such water-soluble pastes were the most common, not all paper was put up with water-soluble adhesives. (In salvage operations one finds that some pastes resist all chemical solvents!)
In spite of smooth plastered walls being recommended as the proper surfaces on which to paste papers, early papers are sometimes found in American houses pasted directly on unfinished boards (figure 20). Skills of paper hangers, as well as budgets of houseowners dictated the methods used. A common practice, intriguing to the researcher, was that of simply pasting new papers on layers of older ones (figure 1). During the late 19th century, textile liners were used to prepare a smooth surface on the wall to which the paper was then pasted.
Last Updated: 26-Apr-2007