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Historic Preservation - Technical Procedures

Spectitle:

Guidelines For Identifying Historic Paint Colors

Procedure code:

0990009S

Source:

Preservation Notebook Series - Gsa

Division:

Finishes

Section:

Painting

Last Modified:

02/24/2012

Details:

Guidelines For Identifying Historic Paint Colors



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), 100
         Barr Drive, West Conshohocken, PA 19428, (610) 832-9585
         or FAX (610) 832-9555.

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 architects'
                             original specifications or
                             architect's intent.

                        d)   Physical paint evidence from studies
                             of other buildings of the same
                             period, style, and type, preferable
                             in 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