An historic paint finishes study may be divided into three sections:
Each study begins with the site visit where areas and element from which paint samples are collected are noted. Exposure areas are opened to uncover the original finish, or subsequent finishes of significance. The site visit provides invaluable information about the building and its construction.
Once the samples are collected they are subjected to a series of procedures: some will be mounted in polymer resin, cut and polished for photomicrography that forms a significant part of the report. Examination and identification of materials as well as color matching is accomplished in the laboratory.
All samples are examined using the Olympus SZ-1145 stereomicroscopy under controlled lighting, provided by fiber-optics illumination. Samples may be subject to a series of procedures: some will be mounted in polymer resin, cut and polished for photomicrography (photographs through the microscope) that forms a significant part of the final report. Exposure to full-spectrum or part-spectrum light is used to help reduce the yellowing of oil media. Some samples will be used for chemical spot testing for the identification of specific pigments. Polarized-light microscopy is also undertaken when necessary, using the Olympus BMAX-50 microscope. Polarized-light microscopy identifies pigments and media according to the McCrone Research Institute system of particle identification, which may be the most important function of serious paint research as it leads to comprehension about the original appearance of the paint finishes.
The information gathered in the on-site examination and the laboratory analysis is brought together in a comprehensible manner that includes annotated photomicrographs illustrating the basis of the restoration recommendations. Color standards, identified by universally accepted numeric identification, known as the CIE Lab coordinates, are included in the printed report. Finish schedules and other pertinent information such as the gloss level, or the presence of glazes, are also included in the report.
Matthew’s firm has worked extensively with support laboratories that provide other means of examination such as Scanning Electron Microscopy, FT-IR (Fourier Transform Infrared Microspectroscopy), Enzyme-fluorescent Microscopy and Raman Spectroscopy. All forms of examination may be undertaken, at the client’s request.