Participants watch as instructor Petraco demonstrates sample mounting techniques.

Participants watch as instructor Petraco demonstrates sample mounting techniques.

The National Center for Preservation Technology and Training (NCPTT) and The Museum of Fine Arts Houston partnered to host a three-day hands-on workshop on Fiber Identification and Analysis for conservation. The workshop was held March 24-26, 2015 at the MFA Houston in the mezzanine level classroom space in the Beck building, this was an ideal location. Walking past Roman statuary each morning on the way to class, is magical for someone who works in a laboratory / office setting each day. Eighteen conservators from around the country gathered together for the three days to learn basic polarized light microscopy (PLM) and methods of sampling, characterization and identification mammalian hair and selected natural and synthetic fibers. The workshop’s emphasis was placed on hands-on exercises including sample preparation and specimen manipulation as well as the characterization and identification of real life specimens.

Participant Ingrid Seyb uses the PLM to view fiber samples.

Participant Ingrid Seyb uses the PLM to view fiber samples.

The workshop’s main instructor is Nicholas Petraco with secondary instruction by Fran Gale. Mr. Petraco served in the New York City Police Department for more than 20 years as Police Laboratory detective/criminalist, and senior trace evidence forensic microscopist. As an independent consultant Mr. Petraco has aided hundreds of investigations and has been designated Technical Leader in Criminalists for NYPD’s Forensic Investigation division. Petraco is the author or co-author of more than 100 journal articles, 9 book chapters, and 5 books, including The Color Atlas and Manual of Microscopy for Criminalists, Chemists, and Conservators. Mr. Petraco lectures and instructs very often on the use of light microscopy, especially stereomicroscopy and polarized light microscopies, in identifying paint pigments, binders and finishes, synthetic and natural fibers and hair, and diverse other materials of interest. Professor Petraco is a member of the CUNY graduate center’s PhD committee for forensic science, and he has taught microscopy, micro-chemical and instrumental analysis as well as forensic science to forensic scientists, art conservators and others at John Jay College of Criminal Justice, CUNY, the American Museum of Natural History in NYC for NYMS, at the FBI academy in Virginia, at NYU’s Institute of Fine Arts, and at other centers and institutions.

Workshop participants were pair up and each team used a Leica DM750P polarized light microscope to view their samples. Numerous hair, natural fibers and synthetic fibers were provided and students were encouraged to start their own study collections. Participants were taught a variety of sampling and mounting techniques including hot mounting, liquid mounting, and casting hair samples.

Photographs from the workshop can be viewed on the NCPTT flickr page.

Participant Fran Baas compares synesthetic fibers under polarized light.

Participant Fran Baas compares synesthetic fibers under polarized light.

Conservators gather around the hotplate as they prep slides for their own study collections.

Conservators gather around the hotplate as they prep slides for their own study collections.

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National Center for Preservation Technology and Training
645 University Parkway
Natchitoches, LA 71457

Email: ncptt[at]nps.gov
Phone: (318) 356-7444
Fax: (318) 356-9119