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Archival permanence

Published sheets disagree on what selenium toner protects

Shows that Kodak G-23 claims toning extends print-image life during display or storage against light, ultraviolet radiation, oxidizing gases and related hazards, and labels a Rapid Selenium Toner dilution for “print protection,” while Ilford Multigrade FB Classic puts selenium in an “optimum permanence” sequence framed for “archival storage” and then scopes toning to display protection from oxidising gases on the same sheet; that Ilford Chemical Sundries defines optimum permanence as residual-silver and thiosulfate minima and publishes a non-selenium path for that definition; that Kodak AJ-3 shortens the product claim to tone change and “prolonging print life”; and that ISO 18929’s LE-100 print criteria are dark-storage residual and physical limits that include toned prints in scope without requiring toning, exclude displayed prints, and deprecate “archival.”

Published by AnalogFixer ·

Selenium toner is routinely spoken of as if one manufacturer claim covered the job: tone the print and it becomes archival. The product sheets examined here do not agree on what the treatment is for, and the print permanence standard that actually issues a life-expectancy rating does not make toning one of its LE criteria.

This is a document comparison of permanence language. It is not a toning sequence, a dilution recipe, or a handling guide.

Kodak G-23 claims display-or-storage protection

Eastman Kodak publication G-23, Toning Black-and-White Materials, May 2006, opens by asking what toner treatment does, and answers with three bullets. The permanence bullet is not limited to colour change:

Extends the life of the print image during display or storage. Toning converts the black-and-white silver image to an inert compound, which reduces the harmful effects of intense light, ultraviolet radiation, oxidizing gases, extremes of temperature and humidity, and fumes. All Kodak toners will protect the image whether or not they produce a color shift.

Under packaged toners, the same sheet states that KODAK PROFESSIONAL Rapid Selenium Toner “converts the silver image to silver selenide,” and pairs a specific dilution label with protection rather than with hue:

Use the 1:20 dilution for print protection.

A later procedure note on the same publication again uses “print protection” as the short-treatment purpose when Hypo Clearing Agent is used as the diluent. The published role is life extension during display or storage, against a listed set of hazards that includes light and ultraviolet radiation.

The May 2005 G-23 revision carries the same display-or-storage life-extension paragraph and the same “1:20 dilution for print protection” wording for Rapid Selenium Toner. The permanence language is not a one-capture accident of the 2006 file.

Fork diagram showing selenium toner credited with silver protection on some sheets and image stability on others.

Ilford’s paper sheet splits permanence and display

HARMAN / Ilford’s Multigrade FB Classic technical information sheet, October 2013, uses selenium in two places with two framings.

Under “OPTIMUM PERMANENCE,” it says standard fixing and washing give excellent permanence for commercial needs, and that when optimum permanence is needed, “perhaps for archival storage of prints,” Washaid sequences are recommended. Immediately after the non-selenium optimum sequence, the sheet publishes an “Optimum permanence sequence with selenium toner.” Selenium is therefore inside the optimum-permanence / archival-storage heading on that sheet.

The STORAGE section on the same final page does not repeat that archival-storage framing for toning. It says processed prints have more than adequate storage life for most purposes, that life shortens in adverse storage or if the print is exposed to oxidising gases, and then:

It is recommended that prints made for display are toned to protect them from the oxidising gases that are found in many environments. Selenium toner is recommended as it has little effect on the image colour of MULTIGRADE FB CLASSIC, but other protection methods can be used including sulphide toning and silver image stabilisers.

So the same Ilford paper sheet places selenium under an optimum-permanence sequence aimed at possible archival storage, and then recommends toning for display protection from oxidising gases. It does not, in that storage paragraph, claim the Kodak G-23 hazard list (intense light, ultraviolet radiation, temperature and humidity extremes, fumes). It also still uses the word “archival” in “archival storage of prints.”

Ilford’s sundries sheet defines permanence without requiring toner

The December 2017 Chemical Sundries sheet, which covers Washaid, states the permanence definition in residual terms rather than as a toner requirement:

There are several ways of achieving prints which will have optimum permanence under long term storage conditions. Essentially, prints must have minimum levels of residual silver (adequately fixed) and minimum levels of thiosulphate (adequately washed).

It then publishes an “Optimum permanence sequence” that is fix / first wash / Washaid / final wash — no toner step — and separately an “Optimum permanence sequence with selenium toner.” Selenium is one of the “several ways,” not the definition. The residual-silver and thiosulfate minima are qualitative; the sheet does not state ISO numerical limits. The three final-wash clocks on that sundries page — twenty, five, and thirty minutes — are compared in Washaid’s final wash is five minutes and twenty on one page.

Kodak AJ-3 shortens the product claim

Kodak Alaris publication AJ-3, How to Process and Print Black-and-White Film, February 2016 / Revised 2/16, lists Rapid Selenium Toner among other chemicals in one sentence:

For altering the image tone of black-and-white prints and prolonging print life.

That is a tone-plus-life claim without G-23’s display-or-storage scope, without the light/UV/oxidizing-gas list, and without the “print protection” dilution label. AJ-3 and G-23 are different publications from different Kodak-brand corporate issuers and years; AJ-3 does not cite G-23, and it does not say the longer claim is withdrawn.

ISO 18929’s LE rating is not a toning certificate

ISO 18929:2012 is titled as specifications for dark storage. Its introduction states that it does not cover tests for the harmful effects of extended exposure to light, and that an applicable light-induced deterioration test had not been agreed. Its scope includes wet-processed silver-gelatin prints “including those that have been chemically treated (with a gold, selenium, sulfur, or other chemical treatment bath) to improve the permanence of the silver image,” and excludes prints that have been displayed.

The introduction also records that diluted toning solutions “have been used successfully to enhance stability,” pointing to informative Annex A. Inclusion of toned prints in scope, and an informative remark that toning has been used to enhance stability, are not the same thing as a normative toning requirement.

The normative processed-image requirements that feed the LE designation are residual thiosulfate concentration, residual silver concentration, and a yellowing limit, together with the physical-stability clauses. Clause 7 states that prints meeting all the specifications in the standard shall have an LE rating of 100. None of those clauses makes selenium toning, or any toner, a condition of the rating. The residual-thiosulfate ceiling attached to print LE-100 is not the same figure as film LE-100 on ISO 18901 Table 2; see LE-100 residual thiosulfate is not one ceiling. The LE definition itself no longer names 21 °C and 50 % RH on the 2012 print edition; see Print LE-100 no longer names 21 °C and 50 % RH.

The same standard deprecates “archival medium” as a term for material expected to preserve images forever. Ilford’s Multigrade sheet still uses “archival storage of prints” for the optimum-permanence case. Kodak G-23’s life-extension claim covers display and names intense light and ultraviolet radiation among the hazards reduced by toning — claim territory that sits outside the dark-storage, display-excluded LE framework ISO 18929 actually publishes.

What the disagreement does not settle

None of these documents assays a finished print against ISO 18929’s residual limits after a named toner path. G-23’s “inert compound” mechanism language is manufacturer description, not an independent measurement in this comparison. Ilford does not explain why the optimum-permanence heading and the display-storage paragraph frame selenium differently. AJ-3 does not say whether its short claim is meant to summarise G-23.

What the sources examined here do support is narrower. Kodak’s toner reference claims display-or-storage life extension and labels a Rapid Selenium Toner dilution for print protection. Ilford’s Multigrade sheet puts selenium under archival-storage optimum permanence and then scopes toning to display protection from oxidising gases. Ilford’s sundries sheet defines optimum permanence as residual silver and thiosulfate minima and publishes a path that meets that wording without toner. Kodak’s process booklet shortens the product claim to tone and prolonged life. ISO 18929 can apply to selenium-treated prints in dark storage, issues LE-100 from residual and physical criteria without requiring toning, excludes displayed prints, and rejects the word “archival.” A reader who treats “selenium = archival” as a single published rule is merging roles the primaries keep apart.

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