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Historic [[architectural]] paint analysis finds its roots in the early twentieth century in the United States. The historic preservation movement began in 1849 with the preservation of [[Mount Vernon]], the home of [[George Washington]]. Early [[preservationist]]s became interested in [[Authenticity in art|authenticity]]. They began to realize that paints and finishes which had survived were very important but may not have been the original, or most significant, finishes. Interest in historic wallpapers also developed with the interest in historic paint and color.
Historic [[architectural]] paint analysis finds its roots in the early twentieth century in the United States. The historic preservation movement began in 1849 with the preservation of [[Mount Vernon]], the home of [[George Washington]]. Early [[preservationist]]s became interested in [[Authenticity in art|authenticity]]. They began to realize that paints and finishes which had survived were very important but may not have been the original, or most significant, finishes. Interest in historic wallpapers also developed with the interest in historic paint and color.


In the 1950s and 1960s, paint colours were investigated at [[Independence National Historical Park]] in Philadelphia by the architect Penelope Hartshorne Batcheler. Her pioneering efforts introduced the use of a [[stereo microscope]] to examine the 18th century paints used at [[Independence Hall]]. Batcheler also introduced the use of the [[Munsell Color System]] for matching and referencing colours. Her landmark publication, ''Paint Color Research and Restoration'', was the first publication concerning the analysis of historic architectural paints for determination of original colour. At the same time, in the [[United Kingdom]], microscopy of paint samples was developed by Joyce Plesters of the [[National Gallery, London]] who worked mainly with easel paintings but also with samples from wall-paintings.<ref>Joyce Plesters, 'Cross-sections & Chemical Analysis of Paint Samples', ''Studies in Conservation'', vol. 2 (1956), pp. 110-157.</ref>
In the 1950s and 1960s, paint colours were investigated at [[Independence National Historical Park]] in Philadelphia by the architect Penelope Hartshorne Batcheler. Her pioneering efforts introduced the use of a [[stereo microscope]] to examine the 18th century paints used at [[Independence Hall]]. Batcheler also introduced the use of the [[Munsell Color System]] for matching and referencing colours. Her landmark publication, ''Paint Color Research and Restoration'', was the first publication concerning the analysis of historic architectural paints for determination of original colour.


In the 1960s and early 1970s, [[Morgan W. Phillips]] at the [[Society for the Preservation of New England Antiquities]] (SPNEA) became involved with historic paint and color analysis, at the [[Harrison Gray Otis House]] in Boston. At the same time, E. Blaine Cliver, Historical Architect, who had worked with Batcheler at the [[National Park Service]] (NPS) in Philadelphia, and with the [[National Trust for Historic Preservation]] in Washington, DC and later at the Northeast Regional Office of the NPS, became involved with historic paint analysis. He set up a laboratory in Building 28 of the former [[Boston Navy Yard]]. In the early 1970s, [[Frank S. Welsh]] joined the NPS in Philadelphia and began to study historic paints with Penelope Batcheler. Welsh introduced the use of the National Bureau of Standards Color Name Charts, ([[NIST]]) for naming colours matched to the Munsell Color System. Welsh introduced the term "paint analysis" into the lexicon of historic preservation.<ref>Welsh, Frank S. 'Paint & Color Restoration', ''The Old-House Journal'', vol. 3, no. 8 (August, 1975), pp. 1, 8-9.</ref> As an independent historic paint colour consultant one of his first major projects was at [[Monticello]], the home of [[Thomas Jefferson]]. In the mid 1970s, Matthew J. Mosca started working for the National Trust with Blaine Cliver. Later, as a preservation consultant, Mosca researched the historic colours of [[Mount Vernon]].
In the 1960s and early 1970s, [[Morgan W. Phillips]] at the [[Society for the Preservation of New England Antiquities]] (SPNEA) became involved with historic paint and color analysis, at the [[Harrison Gray Otis House]] in Boston. At the same time, E. Blaine Cliver, Historical Architect, who had worked with Batcheler at the [[National Park Service]] (NPS) in Philadelphia, and with the [[National Trust for Historic Preservation]] in Washington, DC and later at the Northeast Regional Office of the NPS, became involved with historic paint analysis. He set up a laboratory in Building 28 of the former [[Boston Navy Yard]].


In the early 1970s, [[Frank S. Welsh]] joined the NPS in Philadelphia and began to study historic paints with Penelope Batcheler. Welsh introduced the use of the National Bureau of Standards Color Name Charts, ([[NIST]]) for naming colours matched to the Munsell Color System. Welsh introduced the term "paint analysis" into the lexicon of historic preservation.<ref>Welsh, Frank S. 'Paint & Color Restoration', ''The Old-House Journal'', vol. 3, no. 8 (August, 1975), pp. 1, 8-9.</ref>
⚫
Historically, paint analysis was done on site by making exposure windows and carefully removing later paint layers to reveal a sequence of finishes down to the substrate. This method was employed during the early investigation of finishes at Historic Williamsburg. There can be problems of misinterpretation and failure to address issues such as paint ageing and discoloration, although this skilled conservation work is still required to reveal original surfaces and patterned paintwork. In modern analysis, small samples of the paint layers are taken for examination under a microscope and laboratory testing.<ref>[[Patrick Baty]], [http://www.papers-paints.co.uk/scrapes.htm 'To Scrape or Not to Scrape'] {{webarchive|url=https://web.archive.org/web/20081120185948/http://www.papers-paints.co.uk/scrapes.htm |date=2008-11-20 }} for the drawbacks of carrying out a scrape, originally published in ''Traditional Paint News'' vol. 1, no. 2 (1996).</ref>


==Laboratory analysis==
==Laboratory analysis==
⚫
Historically, paint analysis was done on site by making exposure windows and carefully removing later paint layers to reveal a sequence of finishes down to the substrate. This method was employed during the early investigation of finishes at Historic Williamsburg. There can be problems of misinterpretation and failure to address issues such as paint ageing and discoloration, although this skilled conservation work is still required to reveal original surfaces and patterned paintwork. In modern analysis, small samples of the paint layers are taken for examination under a microscope and laboratory testing.<ref>[[Patrick Baty]], [http://www.papers-paints.co.uk/scrapes.htm 'To Scrape or Not to Scrape'] {{webarchive|url=https://web.archive.org/web/20081120185948/http://www.papers-paints.co.uk/scrapes.htm |date=2008-11-20 }} for the drawbacks of carrying out a scrape, originally published in ''Traditional Paint News'' vol. 1, no. 2 (1996).</ref>

The primary purposes of analysis are to determine historic finishes and to determine principle components including media and pigments. There are two methods in the preparation of paint samples for microscopic analysis. The first is to mount the sample in a permanent medium such as [[Paraffin wax|paraffin]] or resin. The specimen is then ground to a flat finish, providing a horizontal surface for viewing layers in cross-section under a microscope. Samples are ground by mechanical methods to best reveal the paint layers. The second is to leave the samples in a loose condition with their broken surfaces which then can be manipulated under the microscope to permit a variety of views of the layers.
The primary purposes of analysis are to determine historic finishes and to determine principle components including media and pigments. There are two methods in the preparation of paint samples for microscopic analysis. The first is to mount the sample in a permanent medium such as [[Paraffin wax|paraffin]] or resin. The specimen is then ground to a flat finish, providing a horizontal surface for viewing layers in cross-section under a microscope. Samples are ground by mechanical methods to best reveal the paint layers. The second is to leave the samples in a loose condition with their broken surfaces which then can be manipulated under the microscope to permit a variety of views of the layers.


Revision as of 03:04, 15 May 2022

Historic paint analysis, or, architectural paint research, is the scientific analysis of a broad range of architectural finishes, and is primarily used to determine the color and behavior of surface finishes at any given point in time. This helps us to understand the building's structural history and how its appearance has changed over time.

Historic paint analysis shares a common methodology with Conservation, and Restoration of Paintings. used to conserve and restore two- and three dimensional works of art. This involves: the identification of components such as organic or inorganic pigments and dyes contained in the pigments. Historic Paint Analysis also identifies the pigments' media of suspension such as (water, oil, or latex and the paints' associated substrate. A variety of techniques are used to identify and analyze the pigment layers and finish exposure, including Finish Exposure, Optical Microscopy, Fluorescent Light Microscopy, Polarized Light Microscopy, and Fourier-Transform Infrared Spectroscopy (FTIR).

These tools not only allow the conservation scientist to model the paint's physical and chemical behavior but are useful for dating purposes as well. Likewise, analyses are used to evaluate levels of risk arising from agents of deterioration that can affect paint loss, surface deterioration, interaction with newer materials, substrates, de-lamination, media and pigment deterioration, and alligatoring. With this information in hand, the conservation scientist can help the conservator better understand the chronology of the painted surface and make recommendations useful in restoring its appearance to a previous state while ensuring its longevity.


History

Historic architectural paint analysis finds its roots in the early twentieth century in the United States. The historic preservation movement began in 1849 with the preservation of Mount Vernon, the home of George Washington. Early preservationists became interested in authenticity. They began to realize that paints and finishes which had survived were very important but may not have been the original, or most significant, finishes. Interest in historic wallpapers also developed with the interest in historic paint and color.

In the 1950s and 1960s, paint colours were investigated at Independence National Historical Park in Philadelphia by the architect Penelope Hartshorne Batcheler. Her pioneering efforts introduced the use of a stereo microscope to examine the 18th century paints used at Independence Hall. Batcheler also introduced the use of the Munsell Color System for matching and referencing colours. Her landmark publication, Paint Color Research and Restoration, was the first publication concerning the analysis of historic architectural paints for determination of original colour.

In the 1960s and early 1970s, Morgan W. Phillips at the Society for the Preservation of New England Antiquities (SPNEA) became involved with historic paint and color analysis, at the Harrison Gray Otis House in Boston. At the same time, E. Blaine Cliver, Historical Architect, who had worked with Batcheler at the National Park Service (NPS) in Philadelphia, and with the National Trust for Historic Preservation in Washington, DC and later at the Northeast Regional Office of the NPS, became involved with historic paint analysis. He set up a laboratory in Building 28 of the former Boston Navy Yard.

In the early 1970s, Frank S. Welsh joined the NPS in Philadelphia and began to study historic paints with Penelope Batcheler. Welsh introduced the use of the National Bureau of Standards Color Name Charts, (NIST) for naming colours matched to the Munsell Color System. Welsh introduced the term "paint analysis" into the lexicon of historic preservation.[1]

Laboratory analysis

Historically, paint analysis was done on site by making exposure windows and carefully removing later paint layers to reveal a sequence of finishes down to the substrate. This method was employed during the early investigation of finishes at Historic Williamsburg. There can be problems of misinterpretation and failure to address issues such as paint ageing and discoloration, although this skilled conservation work is still required to reveal original surfaces and patterned paintwork. In modern analysis, small samples of the paint layers are taken for examination under a microscope and laboratory testing.[2]

The primary purposes of analysis are to determine historic finishes and to determine principle components including media and pigments. There are two methods in the preparation of paint samples for microscopic analysis. The first is to mount the sample in a permanent medium such as paraffin or resin. The specimen is then ground to a flat finish, providing a horizontal surface for viewing layers in cross-section under a microscope. Samples are ground by mechanical methods to best reveal the paint layers. The second is to leave the samples in a loose condition with their broken surfaces which then can be manipulated under the microscope to permit a variety of views of the layers.

It is often possible to see sequences of paint layers resulting from decades of decoration, and identify colour schemes in chronological order. Samples from different features of a room or building can be compared to tabulate changes in decoration on different features within successive schemes of interior decoration, revealing changes in fashion and taste. Samples from newer elements of a building will have fewer paint layers. Paint analysts are usually well-qualified to report on historic phases of decoration, architectural changes, and historical paint materials and craft practice and input into the presentation and interpretation of heritage buildings.[3]

Colour matching from samples

Samples are typically viewed under an optical microscope using either natural north light or polarized artificial light simulating natural north light. North light is essential in order to render the colors accurately without the effects of the yellow spectrum of direct sunlight. Each layer is identified and, typically, matched to the Munsell color system. The Munsell color system is a scientific system in which colors have been ranged into a color fan based upon three attributes: hue or color, the chroma or color saturation, and the value or neutral lightness or darkness. Unlike color systems developed by paint manufacturers, the Munsell system provides an unchanging standard of reference which is unaffected by the marketplace and changing tastes in colors.

The hue notation, the color, indicates the relation of the sample to a visually equally spaced scale of 100 hues. There are 10 major hues, five principal and five intermediate within this scale. The hues are identified by initials indicating the central member of the group: red R, yellow-red YR, yellow Y, yellow-green YG, green G, blue-green BG, blue B, purple-blue PB, purple P, and red-purple PR. The hues in each group are identified by the numbers 1 to 10. The most purplish of the red hues, 1 on the scale of 100, is designated as 1R, the most yellowish as 10R, and the central hue as 5R. The hue 10R can also be expressed as 10, 5Y as 25, and so forth if a notation of the hue as a number is desired. Chroma indicates the degree of departure of a given hue from the neutral gray axis of the same value. It is the strength of saturation of color from neutral gray, written /0 to /14 or further for maximum color saturation.

Value, or lightness, makes up the neutral gray axis of the color wheel, ranging from black, number 1, to white at the top of the axis, number 10. A visual value can be approximated by the help of the neutral gray chips of the Rock or Soil Color chart with ten intervals. The color parameters can be expressed with figures semi-quantitatively as: hue, value/chroma (H, V/C). The color "medium red" should serve as an example for presentation with the three color attributes, 5R 5.5/6. This means that 5R is located in the middle of the red hue, 5.5 is the lightness of Munsell value near the middle between light and dark, and 6 is the degree of the Munsell chroma, or the color saturation, which is about in the middle of the saturation scale.


Interpretation

The most common application of historic paint analysis is to reconstruct the physical appearance of a structure at some point in it's history, and or, to understand the evolution and changes to a building's structure [4]. Therefore, it is the historic appearance and the visual impression that will be created by new paint treatments that must be considered before choosing a particular course of action.

Preservation

When the goal of treatment is preservation, a building's existing historic features and finishes are maintained and repaired, saving as much of the historic paint when possible. At times, all that is needed is a simple cleaning of surfaces or the addition of a protective coating to preserve and protect the finish’s integrity. If repainting is all that is required, the new paint is matched to existing paint colors using safer, modern and more durable formulations. In these cases, restoring the appearance of an earlier surface is not the objective.

Rehabilitation

In a typical rehabilitation, more latitude exists in choosing both the type and color of paint as the objective is the efficient reuse of interior spaces. Selection often weighs factors such as economy and durability, use of a high-quality standard paint from a local or national company and application by a qualified contractor. Color choices may be based on paint research reports prepared for interior rooms or exteriors of comparable date and style. More often, though, current color values and taste are taken into account.

Both interiors and exteriors of institutional buildings, such as university buildings, city halls, libraries, and churches often contain rich decorative detailing. During rehabilitation, care should be taken to retain or restore selected portions of the decorative work as well as the color matching process, to evoke the historic sense of time and place. At minimum, it is essential to use historically correct paint colors in placement.

Restoration

In a restoration project, the goal is to depict the property as it appeared during its period of greatest significance. Based on historical research, onsite collection of paint samples, and laboratory analysis, surface colors and treatments can be recreated to reflect the property at a particular period of time. In the restoration process, colors are custom-matched by professionals to give an accurate representation using the methods described above to sustain the historic integrity of the building. If an artist or artisan can be found, the historically replicated paint may be applied using techniques appropriate to the period of the restoration. Although custom paint manufacture is seldom undertaken, color and glazing are equally capable of being customized.

One of the earliest examples of structural restoration based upon historic paint analysis is the restoration ofWilliamsburg, Virginia funded by John D. Rockefeller in the 1920s. Investigations carried out by Susan Nashof by simple scraping and revealing of older finishes of buildings yielded a palette that became popularly known as Williamsburg colors.[5] However, advances in paint color research suggested that the popular Williamsburg color palette was derived from faded and aged finishes. During the 1980s and 1990s, Colonial Williamsburg consulted with Welsh to undertake a comprehensive paint and color analysis on numerous buildings in the historic area. The study, "the first modern scientific paint analysis" at Williamsburg, confirmed that the color palette did not represent historic color as first intended. In addition he found that some of the colors chosen were from later paint layers, some nineteenth-century.[6] "Interestingly, many of the colors were still based on Susan Nash‘s early research. Four years ago, Benjamin Moore released the ―The Williamsburg Color Collection‖. Comprising 144 colors, this updated palette is the product of close collaboration with CWF experts using modern Architectural Paint Research methods including microscopy, instrumental analysis, and colorimetry complemented by archival research to provide a range, which is believed to accurately reflect 18th century Williamsburg‘s architectural finishes” [7]. Based on this type of research, Colonial Williamsburg has undergone a paint restoration process to restore building colors and paint to their original intended appearance [8].

References

  1. ^ Welsh, Frank S. 'Paint & Color Restoration', The Old-House Journal, vol. 3, no. 8 (August, 1975), pp. 1, 8-9.
  2. ^ Patrick Baty, 'To Scrape or Not to Scrape' Archived 2008-11-20 at the Wayback Machine for the drawbacks of carrying out a scrape, originally published in Traditional Paint News vol. 1, no. 2 (1996).
  3. ^ Helen Hughes, Layers of Understanding (Routledge, 2002), pp. 13-21.
  4. ^ Patrick Baty, [1] The Role of Paint Analysis in the Historic Interior. originally published in the Journal of Architectural Conservation vol. 1 no. 1, March 1995: 27-37.
  5. ^ Taylor, Jr.,Thomas H., and Papas, Jr., Nicholas A. 'Colonial Williamsburg Colors: A Changing Spectrum', Roger W. Moss, Paint in America: The Colors of Historic Buildings (New York: John Wiley, 1994).
  6. ^ Taylor, Jr., Thomas H., and Papas, Jr., Nicholas A. 'Colonial Williamsburg Colors: A Changing Spectrum', Roger W. Moss, Paint in America: The Colors of Historic Buildings (New York, John Wiley, 1994), p. 86.
  7. ^ Alam, T. (2017) The Evolution of “American Historic Color Palettes” Historic Preservation, Graduate School of Architecture, Planning & Preservation, Columbia University. Supervisor: Mary Jablonski
  8. ^ Paint the town. Colonial Williamsburg wax seal. (n.d.). Retrieved from https://www.colonialwilliamsburg.org/trend-tradition-magazine/summer-2016/paint-town/

Sources

  • Batcheler, Penelope Hartshorne. "Paint Color Research and Restoration", Technical Leaflet #15, American Association for State and Local History, History News, Vol. 23, No. 10, (October 1968)
  • Baty, Patrick. The Rôle of Paint Analysis in the Historic Interior. The Journal of Architectural Conservation. (March 1995): 27-37.
  • Baty, Patrick. To Scrape or Not To Scrape?. Traditional Paint News, Vol 1 No 2 (October 1996): 9-15.
  • Baty, Patrick. "The Benefit of Hindsight". Some Tips on Commissioning Paint Analysis An article based on a paper given at the English Heritage Layers of Understanding conference that took place in London on 28 April 2000.
  • Bristow, Ian C., Architectural Colour in British Interiors, 1615–1840, Yale (1996)
  • Bristow, Ian C., Interior House Painting Colours and Technology, 1615–1840, Yale (1996)
  • Gettens, Rutherford J., and Stout, George L. Painting Materials: A Short Encyclopedia. New York: Dover Publications, (1966)
  • Hughes, Helen, ed., Layers of Understanding: Seminar Proceeding 28 April 2000, Donhead (2002)
  • Maycock, Susa and Zimmerman, Sarah Painting Historic Exteriors: Colors, Application and Regulation: A Resource Guide, Cambridge Historical Commission, Cambridge, Massachusetts, (1998/2006)
  • Moss, Roger W. Paint in America: The Colors of Historic Buildings The Preservation Press, Washington, D.C., (1994)
  • Moss, Roger W. Century of Color: Exterior Decoration for American Buildings, 1829–1920, American Life Foundation, Watkins Glen, New York, (1981)
  • Phillips, Morgan W. "Problems in the Restoration and Preservation of Old House Paints, Preservation and Conservation", In Principles and Practices. Proceedings of the North American International Regional Conference, Williamsburg, Virginia, and Philadelphia, Pennsylvania, September 10–16. 1972. The Preservation Press, National Trust for Historic Preservation in the United States, (1976)
  • Sherwin-Williams. Heritage Colors: Authentic Exterior Colors of American Buildings, 1820–1920 American Life Foundation, Watkins Glen, New York, (1981)
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