Sepia Toning

Toning

What Is Sepia Toning?

Sepia toning converts the metallic silver image to silver sulfide, producing the warm brown tones associated with vintage photographs. It is a two-bath process: the print is first bleached

Sepia-toned half-length portrait of Booker T. Washington, seated, c. 1895
A sulfide-toned albumen/silver portrait by Frances Benjamin Johnston, c. 1895 — the warm brown tone is characteristic of 19th-century sepia toning. Image: Frances Benjamin Johnston — Public domain

(converting silver to silver bromide) and then redeveloped in a sulfide or thiourea bath (converting silver bromide to brown-toned silver sulfide).

The Two-Bath Process

Bath 1: Bleach

The bleach bath contains potassium ferricyanide and potassium bromide. It converts the metallic silver image to pale yellow silver bromide and silver ferrocyanide.

Typical formula:

  • Potassium ferricyanide: 50g
  • Potassium bromide: 50g
  • Water to make: 1 liter

Working solution: dilute 1:9 with water.

Bath 2: Toner

Sodium sulfide toner:

  • Sodium sulfide: 25g per liter
  • Strong "rotten egg" smell; work with ventilation

Thiourea toner (preferred for studio work):

  • Thiourea: 25g
  • Sodium hydroxide: 10-25g (controls warmth)
  • Water to make: 500ml

More sodium hydroxide produces purple-brown tones; less produces yellow-brown tones.

Procedure

  1. Start with a fully fixed, well-washed print (fiber-based preferred)
  2. Immerse in bleach bath with gentle agitation
  3. Bleach to the desired degree (see "Controlling Warmth" below)
  4. Rinse thoroughly in running water for 2 minutes
  5. Immerse in toner bath until the image is fully redeveloped (1-2 minutes)
  6. Wash thoroughly: 20-30 minutes for fiber-based paper

Controlling Warmth

The degree of bleaching directly controls the final tone:

  • Full bleach (image nearly disappears): Deep, rich sepia throughout the entire tonal range
Sepia-toned 1880 photograph of Albuquerque, New Mexico
An 1880 sepia-toned print of Albuquerque — full-bleach toning produces this uniform warm brown across the entire tonal range. Image: New York Public Library — Public domain

. Warm highlights, warm shadows.

  • Partial bleach (highlights only bleached): Split-tone effect. Warm highlights with cool/neutral shadows. Often the most attractive result.
  • Light bleach (subtle lightening): Very subtle warmth in the lightest tones only. Delicate and elegant.

Sepia and Archival Permanence

Silver sulfide is significantly more resistant to atmospheric oxidation than metallic silver. Sepia-toned prints have better archival permanence than untoned prints, which is one reason so many 19th-century prints survive

Sepia-toned Victorian carte de visite portrait of explorer David Livingstone
A Victorian carte de visite of David Livingstone — routinely sulfide-toned, these prints survive in good condition because silver sulfide resists oxidation. Image: P.E. Chappuis (The Stereoscopic Co. of London) — Public domain

in good condition -- they were routinely toned in sulfide toners.

Tips

  • Prints lighten slightly during bleaching and darken slightly during toning. Print about 5-10% darker than your target final density.
  • Thiourea sepia is far more pleasant to work with than sodium sulfide. The odor is minimal and tone control is better.
  • The bleach can be reused many times. The toner exhausts more quickly and should be mixed fresh for each session.
  • Sepia toning works on both fiber-based and RC papers, but fiber gives richer, more luminous results.
  • Experiment with partial bleaching for the most nuanced results.