Guidelines For Identifying Historic Paint Colors

Procedure code:
990009G
Source:
Preservation Notebook Series - GSA
Division:
Finishes
Section:
Painting
Last Modified:
07/03/2016

GUIDELINES FOR IDENTIFYING HISTORIC PAINT COLORS

PART 1---GENERAL

1.01 SUMMARY

    A.  This procedure includes guidance on when to specify the use of historic paint colors, how to identify historic paint colors and how to contract for paint analysis. It documents items required of the conservator performing the work, it outlines a methodology for analyzing the paint, and it provides recommendations on how to prepare a complete and thorough paint analysis report.

    B.   Accurate identification of historic paint colors is an important part of the General Services Administration's restoration program. The original architects of GSA's historic buildings selected paints and finishes that would express their designs in the best possible manner. Paint colors and textures were intentionally chosen to articulate the architectural elements within each space and to convey the relative importance of different spaces within the building.

1.02 REFERENCES

    A.  American Society for Testing and Materials (ASTM)

1.03 SUBMITTALS

    A.  Substantially complete (95%) and completed paint analysis reports will be submitted to the Regional Historic Preservation Officers for review and comment prior to completion of the contract.

1.04 QUALITY ASSURANCE

    A.   Qualifications:

         1.  Sampling: The conservator taking the samples must have a knowledge of paint sampling techniques sufficient to identify locations where complete stratigraphies are likely to exist, and where original paint colors are least likely to have degraded. Verification of this knowledge may be requested at the time of negotiation.

         2.  Laboratory Analysis/Interpretation of Samples: This must be done by a conservator trained in the laboratory analysis of architectural paints on buildings of similar complexity of those being studied for GSA.

    B.   Field Samples:

         1.   Sampling Locations:  In spaces designated for sampling, all original paint/stain colors and clear finishes must be identified. Take samples from areas that have been subjected to the least possible exposure. Indicate sample locations on floor plans and/or elevations of the space sampled. Take a sufficient number of samples to ensure:

              a.   an accurate accounting of all of the finish layers on each sampled surface.

              b.   that "like" elements in the same area or type of space in the building have the same number and sequence of layers.

         2.  Sampling Technique: For each surface to be sampled, reveal each paint layer using a surgical scalpel or craft knife with a curved blade. Expose 1/4"-1/2" square inch of each layer.

         3.  Matching: Using a daylight equivalent 3200 or 3400 Kelvin light source, match the first significant paint layers and original stain colors to the Munsell or Plochere System of Color Notation, according to Section 5.2 and 5.3 of ASTM DI535-68.

         4.  Original Clear Finishes: Solvent test to identify the type of finish (shellac, varnish, lacquer).  Note the finish type in seriation charts and report narrative.

         5.   Decorative Finishes:

              a.  Should graining, marbling, or other decorative finishes exist at any layer, expose a
sufficient area of each layer to reveal the pattern or technique and photograph the exposed area.  Note the type of decorative treatment (graining, marbling, stenciling) on the seriation charts and code the base coat.

              b.  Notify the Contracting Officer of frescoes or other decorative finishes discovered during the course of this contract and note in the report. The Conservator will not be held  responsible for the documentation of fresco painting under this scope of services.


PART 2---PRODUCTS

2.01 EQUIPMENT

    A.   The Conservator must supply all required color books, lights, analytical materials, and color chips, as well as provide the necessary scaffolding, swing stages, electrical modifications, or removal of materials adjacent to the fabric to complete the inspection.


PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION

    A.   When to Specify the Use of Historic Colors: In painting contracts involving historic properties, specify the use of historic colors for the following locations:

         1.   All exterior painted surfaces.

         2.   Lobbies, entrance vestibules, corridors, auditoriums, libraries and other public spaces.

         3.   Other significant spaces identified in the building's Historic Structure Report (HSR), Chapter 9 "Inventory of Significant Spaces and Features. "When no HSR is available for a building, consult the Regional Historic Preservation Officer (RHPO) for a space's historic significance.

    B.   Locating Historic Paint Color Information: The building's historic paint colors are provided in Chapter 5 "Paint Analysis", of the HSR. When no HSR is available for a building, or when the HSR does not provide colors for the space in question, contract for paint analysis to identify the historic colors.

    C.   Historic Paint Color Identification:

         1.   Paint analysis uses laboratory techniques developed for the field of art conservation to identify and document original paint colors and components. An ultra-violet light microscope is used in the laboratory to identify pigment and binding media.

         2.  Paint color documentation involves cutting through existing paint layers, examining paint stratigraphies under magnification, and matching the first (i.e. original) layers to a standard color system.  Standard color systems allow precise documentation of original colors, using alpha numeric codes which describe the color attributes of hue (pigmentation), chroma (color intensity), and value (lightness/darkness).  Each alpha numeric  code corresponds to a unique color card which can be matched to any modern paint.

    D.   Computer Color Matching: Computer color matching machines, available at most major supply centers, eliminate the subjectivity of visual matching and error which occurs when paint colors are matched under different lighting conditions than those present in the historic building, a phenomenon called "metamerism".

    E.   Documentation for Paint Analysis: The conservator must perform all services and provide all materials and equipment necessary to complete the study and prepare the report.

         1.   Provide paint sampling, analysis, and a written report of findings and repainting recommendations for each location required. The following report format is recommended:

              a.   Introduction: State the purpose of the paint analysis, recognize the sample locations, and explain the "period of significance" for paint restoration. Provide the following:

                   2)   Building name, number, and location.

                   3)   Areas subject to analysis.

                   4)   Examination dates and analysis names.

                   5)   Research methods.

              b.   Paint Seriation Charts:

                   1)   Present paint seriation charts (color- finish history) graphically in columnar charts.  Head each column with the name of the substrate, primer, first finish later, second finish layer, and so on, with the present paint layer shown last, at the bottom of the column.

                   2)   Align paint chronologies of different elements so that the paint scheme for any period can be read across a single horizontal line.

                   3)   For materials originally left unpainted, name the substrate at the top of the column, as for other elements, and indicate "(unpainted)" in the line corresponding to the original finish layers.  Provide a Munsell or Plochere code for the color of the substrate.

              c.   Observation/Findings: Describe paint evidence in clear, physical terms, e.g., "first layer primer", "first finish layer", rather than "first significant layer", or other terms ambiguous as to the position of the layer in the seriation.

              d.   Conclusion: Explain in general terms how the paint analysis findings relate to the overall design of the space. State clearly what is known and what is not known from the paint analysis.  Do not abbreviate or restate the analysis findings.

              e.   Recommendations: Provide recommended restoration colors:

                   1)   Provide a narrative and a list of recommended finishes, by location, including common color names for paints and stains, Munsell or Plochere color codes, gloss levels, and clear finish types.

                        a)   Recommended Colors and Finishes

                              List: List elements vertically by location (e.g. "First Floor Main Lobby: Ceiling:  Rosette, Coffer, Fret Molding, Fret Background", etc. On horizontal axis, correlate each architectural element (listed in the left column to the recommended paint/stain color name, finish (gloss level, texture, vehicle for clear coatings), and standard Munsell Plochere color code (listed in the right columns).

                        b)   Decorative Finishes: Break original multicoat decorative finishes (eg. Glazed paints), graining out by component layers and describe the overall intent, or common name of the decorative treatment.  Note the type of decorative treatment in the list.

                        c)   If the list does not provide adequate space, name the components,
or layers of the decorative system in a separate section. For example, "mahogany graining" may be broken down into a ground paint layer followed by one or more glazes; a gold leaf finish might include a yellow bole, gold leaf, and a lacquer; and antiqued imitation gold  leaf finish might include a "Dutch metal" leaf made of ground copper and zinc followed by several textured glazes. Key the ground or base of each decorative system to the Munsell or Plochere system.

                   2)   Narrative: Explain the paint recommendations within the larger restoration context. Unless unusual historic considerations dictate otherwise, paint restoration must return the building to its original appearance, i.e., as designed by the original architect. Justify the recommended color scheme. Emphasize that colors, both natural and applied, were part of the original architect's design.

                   3)   Period of Significance: In rare cases, the "period of significance" for restoration may not be that of the earliest paint scheme. The Conservator must provide strong justification, based on scholarly restoration principles, for restoration paint schemes using colors other than the original colors identified by the paint analysis. Such exceptions are most likely to occur when the building has experienced significant  alteration over time, and when the alterations have acquired significance in their own right. Check with the Regional Historic Preservation Officer prior to starting analysis to determine if such direction is already recognized.

                   4)   Recommended colors for materials originally left unpainted: Match the substrate to the Munsell or Plochere system. Describe the material's primary natural color names. Recommend whether or not stripping to restore the natural finish is advisable. For example, stripping may not be advisable if the surface has been patched with dissimilar materials or the substrate is deteriorated or extremely porous.

                   5)  Recommended colors for features lacking original paint: The recommendations for repainting must address gaps in the physical paint evidence. Provide recommended colors for all of the painted surfaces in the space.  Draw analogies, if possible, between elements with known original paint colors (or clear finishes) and non-original or stripped elements for which physical paint evidence is unavailable.

                   6)  When paint evidence is unavailable, or an element is not original, prescribe
restoration colors/finishes using the following types of evidence, in order of priority:

                        a)  Physical paint evidence from the same area of the building.

                        b)  Physical paint evidence from another, similar area of the building.

                        c)  Historical documentation on the building, such as the architect's original specifications or architect's intent.

                        d)  Physical paint evidence from studies of other buildings of the same period, style, and type, preferablein the same region.

                        e)  Scholarly research (primary or secondary, cite sources) on architectural paint styles and practices of the period. Appropriate primary sources include paint research on other buildings,  period tastebooks, period paint manuals, manufacturer's paint  palettes of the period, letters, diaries, paintings, etc.

         2.  Provide the government with a detailed listing of the number of samples required to identify all colors at these locations and the cost to provide sampling and analysis.  Also provide a narrative that documents the following:

              a.   The actual methods used, including all tools and equipment.

              b.   Paint analysis findings, describing original color schemes for each location.

              c.   Any special comments on paint techniques or materials.

              d.   Recommendations for repainting.

         3.  Do not sample elements which visual inspection indicates are not original.

         4.  Prepare paint chronology charts for all paint layers on the sampled surface.  Match the first finish paint layer to the Munsell or Plochere standard color notation system; identify other colors by common color names.

              a.  Record all paint layers on standardized paint seriation charts, using common color names. Show common color names and color codes for first significant layers.  Should a color fall between two such codes, list both codes, separated by a dash (e.g., 5Y9/1-5Y9/2).

              b.  Record each layer of each different portion of the building fabric in corresponding layering sequence, so that the overall color scheme of each period of the building's history can be readily seen.

         5.   Provide 3"x5" color chips (1 set) for the earliest or most significant (if predetermined not to be the original finish layer) color scheme, as a matching guide for repainting.  If there are two periods of significance, provide color chips for both periods.

         6.   Provide graphic illustration of color scheme: Show the location of each color or paint technique on drawings, floor plans, diagrams, or photographs.If original or subsequent drawings of the building exist, the Government will provide them. For complex polychrome surfaces, illustrate the recommended paint scheme on a section (profile) sketch, with broken lines marking where breaks between colors occur.

         7.   Identify original finish systems for clear finished wood elements. Match original stain colors to the Munsell or Plochere systems. Solvent test to identify the type of finish (shellac, varnish, lacquer).

END OF SECTION

Last Reviewed 2016-07-03