New Cyanotype Photography Guide — Mike Ware's Improved Process Explained

The "new cyanotype" — developed by Dr Mike Ware in the 1990s — is a modern reformulation of John Herschel's classic 1842 cyanotype process. It addresses the principal limitations of the traditional cyanotype: slow speed, low contrast, bleeding of the sensitiser into the paper fibres, and the tendency of the Prussian blue image to partially bleach in alkaline environments. Ware's new cyanotype uses ammonium iron(III) oxalate as the photosensitive agent (replacing the ammonium iron(III) citrate of the classic formula) and potassium ferricyanide as the image-forming agent. The result is a process that is faster, sharper, higher in contrast, and more controllable than the traditional cyanotype, while retaining the iconic cyan-blue colour that has made the cyanotype one of the most beloved alternative processes. This guide covers the chemistry, preparation, techniques, and aesthetic possibilities of the new cyanotype.

Why a New Cyanotype?

Herschel's original cyanotype formula uses ammonium iron(III) citrate — a compound that is hygroscopic, variable in composition between manufacturers, and relatively slow to respond to UV light. The citrate is a large molecule that tends to migrate through the paper fibres, producing soft, slightly fuzzy results. Ware identified ammonium iron(III) oxalate (the same compound used in platinum and palladium printing) as a superior photosensitive agent: it is faster, sharper, more consistent, and produces higher contrast. The oxalate molecule is smaller, staying closer to the paper surface and producing crisper detail. The new cyanotype is approximately four times faster than the traditional formula, making exposures shorter and more practical.

Chemistry of the New Cyanotype

The new cyanotype sensitiser consists of two solutions. Solution A is ammonium iron(III) oxalate dissolved in water. Solution B is potassium ferricyanide dissolved in water, with a small amount of ammonium dichromate added as a contrast-controlling agent. When the solutions are mixed and coated onto paper, UV light reduces the ferric oxalate to ferrous oxalate. During development (which is simply washing in water), the ferrous ions react with the potassium ferricyanide to form Prussian blue (iron(III) hexacyanoferrate(II)), the same insoluble blue pigment that forms the image in the traditional cyanotype. The ammonium dichromate acts as a restrainer, preventing the formation of Prussian blue in unexposed areas and thus increasing contrast. The amount of dichromate can be varied to control the contrast of the print.

Sensitiser Preparation

The two stock solutions are prepared separately. Solution A: dissolve ammonium iron(III) oxalate in distilled water at approximately 30% w/v. Solution B: dissolve potassium ferricyanide in distilled water at approximately 10% w/v, with ammonium dichromate added at a variable concentration (typically 0.5% to 2%) to control contrast. The solutions are mixed in equal parts immediately before coating. The combined solution has a greenish-yellow colour and should be used within a few hours. Unlike the traditional cyanotype sensitiser (which can be stored indefinitely), the new cyanotype sensitiser has a limited working life once mixed.

Paper Selection and Coating

The new cyanotype works well on a wide range of fine art papers. Because the oxalate sensitiser stays closer to the paper surface, it produces sharper results than the traditional formula on the same paper. Internally sized papers such as Arches Platine, COT 320, Fabriano Artistico, and Hahnemühle Platinum Rag all give excellent results. The sensitiser is applied under subdued tungsten light using a glass rod, foam brush, or hake brush. Even coating is important for even image tones. Some practitioners prefer to pre-shrink the paper by soaking and drying before coating to prevent cockling during wet processing. The coated sheets are dried in darkness and should be exposed the same day.

Exposure and Development

Contact print under UV light — a UV exposure unit, the sun, or UV fluorescent tubes. The new cyanotype is significantly faster than the traditional process, so exposure times are shorter. A test strip is recommended when establishing times for a new setup. After exposure, the print is developed simply by washing in running water. The unexposed sensitiser washes away, leaving the Prussian blue image. An optional brief immersion in dilute hydrochloric acid (0.5%) followed by further washing can deepen the blue colour and clear the highlights. The print is then dried flat. The blue colour will deepen over 24 to 48 hours as the Prussian blue oxidises and stabilises — a phenomenon known as "dark reaction" or "oxidative darkening."

Differences from the Traditional Cyanotype

The new cyanotype produces sharper, higher-contrast images. It is faster — exposures are typically one-quarter of the traditional formula. The highlights are cleaner — less prone to the pale blue staining that can occur with the traditional sensitiser on some papers. The contrast can be adjusted by varying the amount of ammonium dichromate in Solution B, giving the printer more control. The colour is similar but often slightly deeper and richer. The new cyanotype is the preferred formula for practitioners who want the cyanotype aesthetic with greater control and fidelity.

Toning the New Cyanotype

Like the traditional cyanotype, new cyanotype prints can be toned to produce colours other than blue. Tannic acid toning (strong tea or coffee) produces warm blue-grey to near-black tones. Wine toning gives purple hues. Sodium carbonate (washing soda) can bleach the blue to produce a yellow-brown image. Combining different toners, or partially toning, extends the palette further. The toning chemistry works the same way for both traditional and new cyanotypes, because the image substance — Prussian blue — is the same in both processes.

Practical Advantages

The new cyanotype is an excellent choice for photographers moving from digital to handmade prints. It requires no darkroom, no enlarger, and no toxic chemicals (though ammonium dichromate should be handled with care). The chemistry is inexpensive. The process is forgiving enough for beginners while offering sufficient control for advanced practitioners. The new cyanotype produces prints that are more consistently controllable than the traditional formula, making it a reliable process for edition printing and portfolio work. For photographers who love the iconic blue but want greater sharpness, contrast, and control, the new cyanotype is the natural upgrade.