MCI Project Summaries 2008 - Smithsonian Institution

National Museum of American History
MCI 6004 Ben Franklin’s Suit
MCI Staff: Mary W. Ballard
In honor of Bejamin Franklin’s 300 th birthday, the silk suit held by the National Museum
of American History but belonging to the Massachusetts Historical Society was taken out of
storage in preparation for display and for patterning a reproduction. The suit’s weave has small
horizontal stripes and vertical bands—cannetillé and louisine with two lisières—deceptively
simple in appearance but more complex to weave. A
tailor was commissioned to reproduce the suit. While
taking pattern with white cotton gloves, he noticed the
color crocked onto his gloves! It appears that the suit was
painted over with ink. In addition, the suit is stained and
discolored. In examining the suit, no change in handle or
feel was apparent—there is no discernable differentiation
where the suit is over-treated and where it is not.
Although the suit was scheduled for display for
only one month, exigencies of the museum plans, extended this for two additional months.
Before and after the exhibition the suit was measured to ensure that neither the ink nor the
original dye changed in apparence. Measurement were taken using the tristimulus colorimeter. It
divides color into three categories: lightness/darkness (L*), redness/greenness (a*), and
blueness/yellowness (b*). A change beyond a delta E of 0.73 was determined to be probably
relevant.
Initial characterization of the colorant was completed, but further characterization
awaited the presence of an organic chemist familiar with modern dye analytical methods. An
MCI visiting scientist from New Lisbon University arranged to describe early modern synthetic
dyes (selected by Helmut Schweppe) from the MCI student standards on FTIR and HPLC. Her
work on the fugitive colorant indicates that it is an azo dye with sulphonic acid substituent
groups; she found it to be soluble in ethanol. This would support the probable use of an early
synthetic dye, such as Fast Acid Magenta B, Fast Red B, or Fast Red AV. The last two dyes date
respectively from 1878 and 1877, so a late 19 th century or early 20 th century “touch-up” is quite
possible.
None of this explains the colorless areas on the britches (beige), brilliantly disguised by
Senior Costume Conservator Sunae Park Evans draping and dressing of the mannequin for
exhibition. Generally neither incontinence nor food stains would decolor the original
(natural)dyestuffs from the 18 th century (see the Interim Dye Report Chart). There is still some
mystery associated with these garments.
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