Toning transforms the silver image into more stable compounds while shifting the print's colour. A selenium-toned print gains archival permanence and subtle colour; a sepia-toned print becomes warm brown. Toning bridges chemistry and aesthetics.
This guide covers the major toning processes, their effects, and practical working methods.
Active time: 30-60 minutes per print (varies by toning method)
This guide assumes you've completed:
- Work in a well-ventilated area—essential for all toning processes
- Always wear gloves—selenium toner is toxic if swallowed or inhaled and can cause skin allergy
- Never mix toners with acids—releases toxic gases
- Sepia sulfide releases hydrogen sulfide gas (toxic)—use outdoors or with exhaust ventilation
- Keep chemicals away from children and pets
- Dispose of toners as chemical/hazardous waste
What Is Toning?
The Chemistry
A black and white print consists of metallic silver suspended in gelatin. Toning replaces some or all of this silver with different compounds:
- Selenium toning: Converts silver to silver selenide
- Gold toning: Deposits metallic gold over the silver
- Sepia/sulfide toning: Converts silver to silver sulfide
Each compound has different colour, stability, and permanence characteristics.
Why Tone Prints?
Archival protection: Silver is vulnerable to environmental pollutants, particularly sulfur compounds in the air. Toned prints resist deterioration better than untoned prints.
Colour shifts: Toning changes the image colour—from cool purple-black (selenium) to warm brown (sepia) to cold blue on fibre paper (gold). These shifts change the mood of a print.
Enhanced tonal richness: Many photographers find toned prints have greater apparent depth, especially in the shadows.
Toning and Paper
Not all papers respond equally to toning:
- Warm-tone papers show more dramatic colour shifts with most toners
- Neutral papers shift more subtly
- RC papers do tone, with selenium and sepia; Ilford lists toning for its Multigrade RC papers, though the response can differ from fibre papers
- Warm-tone (chlorobromide) papers (like Ilford Multigrade FB Warmtone or Fomabrom) tone readily, with stronger colour shifts
- Pure bromide papers show less colour change but still gain archival benefit
Always test toning on spare prints before committing important work. Paper response varies significantly between brands and batches.
Getting Started: Commercial Toners
For beginners, start with ready-made toners rather than mixing from scratch:
Selenium toner (Harman Selenium Toner, Fotospeed SLT20): Subtle colour shift, archival benefits. Harman's normal toning dilution is 1+3, and it suggests 1+20 when the main aim is protection with minimal tone change. Fotospeed gives 1+3 to 1+12 for colour and 1+39 for archival permanence. Kodak Rapid Selenium Toner production has been on hold.
Sepia toner (e.g. Fotospeed ST20, a thiourea kit): Classic warm brown. Comes in two-part kits with bleach and toner—follow the instructions included.
Gold toner (e.g. Fotospeed AU20): Supplied ready to use and not diluted. Fotospeed says that on untoned fibre prints it gives a cold, steely blue after about 20 minutes, and that on RC prints it shows little or no steel blue, so RC prints are sepia toned and washed first to get a reddish/peachy tone. Used on an untoned print it can make the print archivally permanent with little or no change in tone.
If you've never toned before, start with selenium toning at the weak, protection-only dilution (1+20 for Harman, 1+39 for Fotospeed SLT20). The change is slow and slight, and it adds archival protection even if the colour shift is barely visible. You can always try stronger dilutions or other toners once you're comfortable with the process.
Selenium Toning
Selenium toning is the most common archival treatment. It provides protection against environmental deterioration while producing a subtle colour shift.
Effects of Selenium
Colour shift: Neutral-to-cool, sometimes with a slight purple cast. The shift is subtle on most papers—visible but not dramatic.
Tonal change: Shadows deepen slightly; overall density can increase. Some prints appear to gain contrast.
Archival benefit: Excellent. Silver selenide is extremely stable against atmospheric sulfur compounds.
Dilutions and Effects
Selenium toner is typically sold as a concentrate (e.g. Harman Selenium Toner, Fotospeed SLT20). The makers' dilutions differ, so use the figures for your own toner.
| Toner | Dilution (toner + water) | Maker's stated purpose |
|---|---|---|
| Harman Selenium Toner | 1+3 | Normal toning |
| Harman Selenium Toner | 1+20 | Protection of the image with minimal tone change |
| Fotospeed SLT20 | 1+3 to 1+12 | Toning; depends on the speed and depth of tone wanted and the paper |
| Fotospeed SLT20 | 1+39 | Archival permanence with no appreciable change in tone |
Both makers say the tone depends on how long the print stays in the toner as well as on the dilution. Harman says the colour and degree of change vary with the paper, from cool chocolate-brown through purplish brown to little discernible change, and that warm-tone papers usually show the most. Fotospeed adds that SLT20, as a true selenium toner, will add contrast (roughly half a grade) and that resin-coated papers, especially variable-contrast ones, can be slow to react.
Selenium Toning Procedure
Process print archivally. Two-bath fixing and proper washing are essential—residual fixer causes uneven toning.
Prepare toner. Mix selenium concentrate with water at chosen dilution, stirring thoroughly, and use it at room temperature (Harman: nominally 20°C ±1°C). Some photographers add washing aid to the toner bath (same concentration as normal use).
Pre-wet print. If print is dry, soak it in water so the emulsion is fully wet (Fotospeed says this takes about a minute). Harman suggests holding prints in a tray of plain water, about 4°C warmer than the toner, before and after toning, and keeping an untoned reference print in it.
Tone. Place print in toner and agitate gently. Watch for colour change, comparing it with the reference print rather than watching it continuously in the toner.
Monitor progress. Check print in good light every minute. Compare to an untoned reference if available.
Remove at desired point. Lift the print into the holding tray of water and agitate for 30-40 seconds to stop the toning (Harman). If it needs more, put it back in the toner.
Wash. Wash thoroughly. Harman gives 2 minutes for RC prints and at least 30 minutes in fresh running water for fibre prints (above 5°C), or its optimum permanence wash sequence for fibre; Fotospeed gives 5 minutes for RC and 20 minutes for fibre. For fibre prints Ilford also describes 10 minutes in washing aid followed by a 30-minute wash.
Timing
Times depend on paper, dilution and toner age. Harman says protection of the image is complete in 2-4 minutes at 1+20, and that the capacity of the working solution is in practice limited by the time the toning takes: as the solution is used or ages, the rate of tonal change becomes progressively slower. Fotospeed gives anything from 1 to 15 minutes depending on the shade of tone. Judge by eye against an untoned reference, and note your times for each paper.
Temperature: Harman says its toner is designed for ambient room temperature, nominally 20°C. For resin-coated paper Fotospeed suggests the stronger 1+3 working solution at about 25°C.
Capacity and Keeping
Harman's guideline is that at 1+3 the working solution has a capacity of at least 25 sheets of 8x10 inch paper per litre. Harman says working-strength solutions normally last up to 6 months in full, tightly capped bottles, 1 month in half-full bottles and up to 7 days in an open tray. Fotospeed gives 2 months in a bottle and at least a week in an open dish. Fotospeed also says the toner smells strongly of ammonia and is exhausted once the smell can no longer be detected.
Reading Selenium Tone
The colour shift can be subtle. Tips for evaluation:
- View prints in consistent, neutral lighting
- Compare toned to untoned prints side-by-side
- Check shadows—they show change first
- Wet prints appear different from dry prints; final evaluation must wait until dry
Papers That Respond Well
- Ilford Multigrade FB Classic: Good response, subtle cooling
- Ilford Warmtone FB: More dramatic shift toward purple
- Fomabrom: Strong response
- Oriental Seagull: Beautiful response (if available)
Selenium toner is poisonous. Work in a well-ventilated area, wear gloves, and never let toner contact skin or eyes. Wash hands thoroughly after any session. Dispose of used toner as hazardous waste.
Gold Toning
Gold toning gives untoned fibre prints a steely, cold blue tone (Fotospeed reports this after about 20 minutes in AU20) and improves the print's resistance to deterioration. RC papers show little or no blue shift.
Effects of Gold
Colour shift: Steely to cold blue on fibre paper; little or no blue on RC paper (Fotospeed AU20 instructions). Gold over sepia gives reddish to peachy tones.
Tonal change: Can slightly reduce overall density. Highlights may shift more than shadows.
Archival benefit: Gold toning is widely used to protect prints, but no maker we cite gives a figure for how much longer a gold-toned print lasts. Good processing, washing and storage matter as much as the toner.
Gold Toner Formulas
Kodak T-21: Kodak's publication J-1 gives a gold toner, T-21, rather than the GP-1 formula. It is a thiosulfate and persulfate bath: stock A also has a silver nitrate and sodium chloride precipitate stirred in, and stock B is gold chloride. Kodak has you leave the mixed toner for about 8 hours so a precipitate settles, pour off the clear solution, and use it at 43°C, with toning taking 5 to 20 minutes. Because it combines silver nitrate, persulfate and gold chloride and is used warm, this guide doesn't reproduce the quantities; work from Kodak's original text if you intend to mix it, and check the hazards of each chemical first.
Gold protective solution (GP-1): Kodak GP-1 is often quoted as a gold chloride and sodium thiocyanate solution, but it is not in J-1 and we haven't been able to check any quantities against a Kodak text, so no formula is given here. Photographers' Formulary describes its Gold Protective Toner as similar to Kodak GP-1. Sodium thiocyanate is harmful by all routes and releases very toxic gas if it contacts acid, and gold chloride is corrosive: wear gloves and eye protection, and keep any thiocyanate-based toner away from stop bath and acid fixers.
Commercial gold toners: Fotospeed AU20 is one example. Fotospeed AU20 is supplied ready to use and must not be diluted. Follow the maker's instructions.
Gold Toning Procedure
Process and wash print archivally. Gold toning is typically done as the final step before drying.
Prepare toner. Commercial toner per the maker's instructions (Fotospeed AU20 is used directly from the bottle).
Tone. Place wet print in gold toner. Agitate gently.
Monitor. Watch the colour change. With AU20, Fotospeed says untoned fibre prints take on a steely blue after about 20 minutes, while sepia-toned prints slowly gain a rich red/peachy tone in the highlights and midtones, redder the longer they stay in.
Remove and wash. Wash thoroughly, following the toner maker's instructions. Kodak's T-21 text calls for a final wash of 1 hour in running water, or hypo clearing agent.
Gold Toner Capacity
Gold toner exhausts as the gold is deposited on prints, so its capacity is limited. Fotospeed says AU20 can be used until it no longer tones, which is approximately 60 8x10 prints, and should be returned to the bottle after each session. Prints going in must be very well washed, because contamination reduces the toner's life. Follow the maker's capacity for other toners.
Cost consideration: Gold chloride is expensive. Gold toning is typically reserved for exhibition prints where maximum permanence justifies the cost.
Selenium + Gold Combination
For the most protective sequence:
- Selenium tone first (at your chosen dilution, to desired level)
- Wash
- Gold tone (to the colour you want; fibre papers shift towards cold blue)
- Final wash
This "belt and suspenders" approach provides maximum protection.
Sepia Toning
Sepia toning converts the silver image to silver sulfide, producing warm brown tones reminiscent of 19th-century photographs.
The Two-Step Process
Unlike selenium and gold (which work directly), sepia toning is typically a bleach-and-redevelop process:
- Bleach: Potassium ferricyanide oxidises the metallic silver and the bromide in the bleach turns it into silver bromide (the image fades to pale yellow/tan)
- Redevelop: Sodium sulfide converts the silver bromide to brown silver sulfide (the image returns as warm brown)
Sepia Toning Procedure
The formula below is Kodak T-7a (Kodak publication J-1).
Bleach stock (A), water to make 2 litres:
- Potassium ferricyanide: 75g
- Potassium bromide: 75g
- Potassium oxalate: 195g
- Acetic acid (28%): 40ml
Use the bleach stock diluted 1+1 with water, and bleach until only a faint image remains.
Sulfide toner stock (B), water to make 500ml:
- Sodium sulfide (anhydrous): 45g
For the redeveloper, dilute 125ml of stock B to 1 litre with water. Kodak also warns against trays with exposed iron. Sodium sulfide is corrosive and releases toxic hydrogen sulfide gas: work outdoors or with exhaust ventilation, and don't rely on the smell as a warning (see below).
Bleach the print until the image nearly disappears. The time depends on dilution and print density.
Rinse thoroughly in running water to remove all bleach. The T-7a bleach contains acetic acid, and acid carried into the sulfide bath would release hydrogen sulfide.
Redevelop in sulfide solution. The image returns in warm brown tones; leave it until the detail has fully returned.
Wash thoroughly. Residual sulfide causes eventual staining.
Controlling Sepia Tone
Full bleach: Complete bleaching produces maximum brown (lighter, warmer).
Partial bleach: Stop bleaching before the image fully disappears for darker, less warm tones with more retained silver.
Variable sepia: Commercial kits (like Fotospeed Variable Sepia) offer multiple redeveloper options for different brown hues.
Thiourea vs Sodium Sulfide
Sodium sulfide:
- Traditional, effective
- Gives off toxic hydrogen sulfide gas
- Requires excellent ventilation
Thiourea:
- Much less odour
- Slightly different colour (can be warmer)
- Some formulas are odourless
Commercial sepia kits often use thiourea for studio practicality. Less smell doesn't mean less hazard: thiourea is a suspected carcinogen and suspected of harming the unborn child, so wear gloves and avoid breathing dust when mixing the powder.
Sodium sulfide releases hydrogen sulfide gas. Don't rely on the smell as a warning: at higher concentrations H₂S quickly deadens your sense of smell, so a fading smell can mean more gas, not less. Work outdoors or with strong exhaust ventilation, never add acid to a sulfide toner, and keep it well away from film and paper, which H₂S will fog.
Split Toning
Split toning combines two toners for dual-tone effects—typically different colours in highlights vs shadows.
Partial Sepia Split
The most common split tone:
Partially bleach in sepia bleach until only highlights are affected (shadows retain silver).
Rinse and redevelop in sulfide. Highlights become brown; shadows remain black.
Optionally selenium tone for cool shadows against warm highlights.
Selenium-Sepia Split
An elegant combination:
Selenium tone first (light treatment). Shadows gain purple-black tone.
Partially sepia tone. Only the midtones and highlights (less-toned areas) convert to brown.
Result: Cool purple-black shadows, warm brown highlights, with smooth transitions.
Creative Possibilities
Split toning opens many combinations:
- Sepia highlights, selenium shadows
- Blue-toned highlights (gold or iron), brown shadows
- Variable intensity across the image
These effects require testing and practice but create distinctive, sophisticated prints.
Other Toning Methods
Copper Toning
Produces red-brown to orange tones. Less common, requires careful handling (copper salts are toxic).
Iron Blue Toning
Creates blue images (think cyanotype colour). The silver image is converted to Prussian blue in a bath of potassium ferricyanide and a ferric salt (usually ferric ammonium citrate) with acid. Because the bath combines ferricyanide with acid, mix and use it cold with good ventilation. Ilford notes that iron and copper toners may not add archival protection.
Tea and Coffee Toning
Non-chemical toning using tannins:
- Make strong tea or coffee
- Soak print for extended periods (hours)
- Wash and dry
Result: Subtle warm staining, not true toning. Not archival—the organic compounds may degrade over time. Fun for effects, not for permanence.
Dye Toning
Some toners add dyes to the image. These can produce vivid colours but are not archival—dyes fade.
Toning Workflow Considerations
When to Tone
In the processing sequence: Tone after fixing, after washing aid (if used), and before final wash.
For dry prints: Re-wet prints for 10-15 minutes before toning. Dry prints that aren't fully softened may tone unevenly.
Print Preparation
For even toning:
- Process archivally (two-bath fix, thorough washing)
- Remove all residual fixer (causes uneven toning)
- Ensure prints are fully wet before toning
Testing
Always test first:
- Make extra prints for toning tests
- Test each paper/toner combination—responses vary
- Keep reference prints (toned and untoned) for comparison
Record Keeping
Note your toning parameters:
- Dilution
- Time
- Temperature
- Paper type
- Observed effect
This allows you to reproduce results.
Safety Summary
Official classifications for the main toning chemicals:
| Chemical | Hazards |
|---|---|
| Sodium seleniteDanger | Toxic if inhaled.; Fatal if swallowed.; May cause an allergic skin reaction.; Toxic to aquatic life with long lasting effects.; Contact with acids liberates toxic gas. |
| Gold(III) chlorideWarning | May cause respiratory irritation.; Causes skin irritation.; Causes serious eye irritation. |
| Sodium thiocyanateWarning | Harmful if inhaled.; Harmful in contact with skin.; Harmful if swallowed.; Harmful to aquatic life with long lasting effects.; Contact with acids liberates very toxic gas. |
| Potassium ferricyanideWarning | Causes serious eye irritation.; Toxic to aquatic life with long lasting effects. |
| Sodium sulfide (anhydrous)Danger | Toxic in contact with skin.; Harmful if swallowed.; Causes severe skin burns and eye damage.; Very toxic to aquatic life. |
| ThioureaWarning | Suspected of causing cancer.; Suspected of damaging the unborn child.; Harmful if swallowed.; Toxic to aquatic life with long lasting effects. |
| Potassium bromideWarning | Causes serious eye irritation. |
Classifications from the European Chemicals Agency (official EU classification where one exists, otherwise the one agreed by REACH registrants or most often notified). Read the safety data sheet that comes with your chemicals, and dispose of them in line with local regulations.
| Toner | Hazard | Precautions |
|---|---|---|
| Selenium | Sodium selenite is fatal if swallowed and toxic if inhaled; releases toxic gas with acids | Gloves, eye protection, ventilation; dispose of in line with local regulations |
| Gold | Gold chloride is corrosive and can cause skin allergy | Gloves, eye protection |
| Gold-thiocyanate (GP-1 type) | Sodium thiocyanate is harmful by all routes and releases very toxic gas on contact with acid | Gloves, eye protection; keep away from acids, stop bath and acid fixer |
| Sepia bleach | Potassium ferricyanide irritates eyes; can release hydrogen cyanide with strong acid or heat | Gloves, eye protection; keep away from acids |
| Sepia sulfide | Sodium sulfide is corrosive and toxic on skin contact; releases H₂S gas (toxic, flammable, deadens smell) | Gloves, eye protection, strong ventilation; never mix with acid |
| Thiourea | Suspected carcinogen and reproductive toxin; harmful if swallowed | Gloves, avoid breathing dust, ventilation |
General rules:
- Always wear gloves when toning
- Work in ventilated spaces
- Never mix toners with acids (releases toxic gases)
- Dispose of toners as chemical waste
- Label all containers clearly
Selenium is a cumulative poison. Even brief skin contact should be avoided. If toner contacts skin, wash immediately with soap and water. For eye contact, flush with water and seek medical attention.
Equipment Needed
- Toning trays
Dedicated trays for each toner. Don't use toning trays for other chemistry.
- Rubber or nitrile gloves
Protect skin from all toners, especially selenium.
- Print tongs
Dedicated tongs for toning.
- Ventilation
Window, fan, or fume hood—especially for sepia.
- Timer
Track toning time accurately.
- Reference prints
Untoned comparison prints for judging tone.
- Good lighting
Neutral daylight or daylight-balanced light for evaluating colour.
Summary
- Toning converts silver to more stable compounds while shifting colour
- Selenium provides archival protection with subtle cooling; toxic—requires gloves and ventilation
- Gold gives a cold blue tone on fibre paper and is used for protection; follow the maker's instructions
- Sepia creates warm brown tones via bleach-and-redevelop; sulfide toners give off toxic hydrogen sulfide, so use strong ventilation
- Split toning combines methods for dual-tone effects
- Always test paper/toner combinations before important work
- Process prints archivally before toning for best results
- Handle all toners with appropriate safety precautions
Toning adds the final dimension to a fine print—the subtle shift in colour that transforms a good photograph into something distinctive. Whether for archival protection or aesthetic effect, toning is a skill that repays careful practice.
Sources
- Sodium selenite: substance information, ECHA
- Sodium sulfide: substance information, ECHA
- Sodium thiocyanate product and safety information, Merck
- Hydrogen sulfide: hazards, OSHA
- Processing and finishing ILFORD fibre base papers (fact sheet)
- MULTIGRADE RC papers technical information, Ilford/Harman
- MULTIGRADE FB Warmtone technical information, Ilford/Harman
- HARMAN Selenium Toner technical information, Ilford/Harman
- Fotospeed toner instruction sheet (SLT20 and AU20, 2008)
- Fotospeed product range booklet (SLT20 and AU20, 2002)
- Processing Chemicals and Formulas (J-1), Eastman Kodak
- C&L Inventory, ECHA