Ambrotypes

The American Antiquarian Society's photograph collection includes approximately one hundred and fifty ambrotypes. Ambrotypes became popular in the mid-1850s, and were much less expensive to produce than daguerreotypes. These consist of a collodion image fixed to a glass plate, which, when held up to light, appears negative. To create a positive image, the back of the plate was either painted black or placed against a black background. Like daguerreotypes, ambrotypes are unique objects. The low-contrast images are sometimes difficult to distinguish from cased tintypes, unless the black background material is damaged.

They were generally produced in the following sizes, which are noted in the inventory:

• Imperial or Mammoth Plate - Larger than 6 ½" x 8 ½"
• Whole Plate - 6 ½" x 8 ½"
  
• Half Plate - 4 ¼" x 5 ½"
  
• Quarter Plate - 3 ¼" x 4 ¼"
  
• Sixth Plate - 2 ¾" x 3 ¼"
  
• Ninth Plate - 2"x 2 ½"
  
• Sixteenth Plate - 1 ½" x 1 ¾"

A fully illustrated inventory is available for this collection.

-Jennifer Racine, Readers' Services