Portrait of a child with a hoop, hand-coloured ambrotype, c 1860.
© National Media Museum / Science & Society Picture Library
Ambrotype hand-coloured with oil paint. The ambrotype process was patented in 1854 and became very popular in America. It was an improvement on existing processes such as daguerreotypes and calotypes because production was quicker and cheaper and less exposure was needed. Ambrotypes were images produced on glass and like daguerreotypes were direct positives and therefore unique. The finished appearance was not glittery and reflective like the daguerreotypes and could be viewed from any angle.