Conservation Portfolio

Treatment of Sam Houston Letter

Information about object

  • Date: 10/23/07
  • PCS Identification number: 08-34
  • Owner/Custodian: Center for American History
  • Title/Subject/Description: February 3, 1843 Letter from Sam Houston
  • Creator: Sam Houston
  • Date of production: February 3, 1843
  • Place of production: Executive Apartment, Washington

Treatment Report


Dimensions (Primary Support):
English: 26.02” H x 36.18” L
Metric: 66.1 cm H x cm 91.9 cm L

Dimensions (Image Area): 
English: 25.12” H x 34.61” L
Metric: 63.8 cm H x cm 87.9 cm L

The letter is written in iron gall ink on a beige (2)[1], medium (2), wove paper that has been silked on both sides.


  • Iron Gall Ink
    The text of the letter is written in a brown iron gall ink of variable darkness.  The ink is lighter on the top recto, then darkens after the fold and remains fairly even over the rest of the document.

Primary Support
The support is a smooth, beige (2), medium (2), wove paper.  It was folded horizontally in thirds.  In the upper left corner of the recto, there is an embossed sigil of a circle with a five-pointed star in the middle.  The diameter of the circle is 1.9 cm.

Both sides of the folio have a silk lining that is a off-white or cream color and is lighter in color than the primary support. This lining extends beyond the edges of losses that have occurred at the edges of the primary support.



The letter is in fairly good condition except for the presence of the silk, some losses of the support and associated media, pin holes and some mild burn-through of the iron gall ink.


Iron Gall Ink
The ink has some halo in areas of heavy application.  There is also some burn-through of the ink on the right center verso margin through to the left recto margin.

Primary Support 

The support is still fairly flexible and in good condition.  There is some mild planar distortion.  There are separate overlapping splits – probably once the original folds or creases – that extend completely from the left to right edges.  The top split is 7.3 cm from the top edge, and the bottom split is 8.8 cm from the bottom edge.  There are single pinholes in each of the top corners.  Along the top split, there is a narrow gap between the two pieces; it starts at the left recto edge and extends 3.4 cm in, where it meets with a 1.8 cm wide loss and two misaligned pieces of the support.  These appear to originate from the loss areas close by.  Along the top split, there is a wider overlap that begins from the loss area, and continues all the way to the right edge.  At its widest, the overlap is approximately 2 mm.  There is a piece of the support, with text, attached to the verso of the support, 6.5 cm from the right verso edge and 9.2 cm from the top verso edge.  There is another piece of the support attached to the recto 5.2 cm from the top edge and 1.9 cm from the left edge.  The right recto edge of the top crease also has a triangular loss that extends 0.7 cm toward the center of the letter.
Along the bottom crease, there are two small losses and tears at the center, the first being 11.0 cm from the left recto edge, and the second being 12.1 cm from the left recto edge.  There is also a small triangular loss in the left recto edge, at the crease, and an irregular shaped loss at the right recto edge of the crease. There are two small notches along the bottom edge of the letter: the first is 1.4 cm from the left recto edge, and the second is 9.8 cm from the right recto edge.

The silk lining is in good condition and is mostly intact except for some fraying along the edges and corners.  It has also delaminated slightly along the split and overlap areas.


The iron gall ink and silk lining were both tested for water and ethanol solubility. The ink was determined to be insoluble in both water and ethanol. The lining and paste adhesive were found to respond sufficiently to water, indicating it could be removed in an aqueous bath.


  1. Aqueous removal of silk.
  2. Wash letter in a phytate bath, followed by a DI water bath.
  3. Realign and mend splits along creases using wheat starch paste and Japanese tissue.
  4. Reattach and mend any pieces currently adhered by the silking that become free after the silk is removed.
  5. Rehouse in original Mylar folder.

Possible Effects of Treatment
Treating iron gall ink with phytates is a recent development in conservation. It stabilizes the iron gall ink more effectively than normal, alkalinized aqueous treatments. Extensive testing at the Library of Congress and the Netherlands Institute for Cultural Heritage (ICN) [2] indicates that it is the most beneficial treatment available, but we continue to investigate the procedure. The pH of the calcium phytate bath will be closely monitored, as a pH in excess of 8.5 is known to cause color shifts in the iron gall ink.


  1. Softened silk and paste using an aqueous calcium hydroxide bath, then removed silk using a microspatula. 30 minutes.
  2. Removed residual paste residue with a soft brush, while letter was still wet. 10 minutes.
  3. The letter was then placed into a phytate bath for 5 minutes, then immersed in a bath of DI water and calcium hydroxide with a pH of 8.5 for another 5 minutes.  10 minutes.
  4. The letter was left to dry between Hollytex and soft felts, with a glass weight on top. 2 days.
  5. Both splits were mended using lens tissue and wheat starch paste.  Two loose fragments were reattached with lens tissue and wheat starch paste.  All tissue mends were applied only on the verso. 2 hours.

Total Treatment Time: 2 days, 2.8 hours

1. Lunning, E and Perkinson, R. 1996. The Print Council of America Paper Sample Book. The Print Council of America.