Calotype is an early photographic process that uses paper coated with silver iodide

Yes, calotype is a type of photography. It was one of the first practical methods for making photographs on paper, invented by William Henry Fox Talbot in the 1830s. Unlike daguerreotypes, which produce a single image on a polished metal plate, calotypes create a negative on paper that can be used to print multiple positive copies on another sheet of paper.

The process works by coating paper with silver iodide, exposing it in a camera, and then developing it with gallic acid and silver nitrate. The resulting paper negative is translucent enough to allow light through, making it possible to contact-print the image onto another piece of sensitized paper to create the final photograph. This fundamental difference — the ability to make many prints from one negative — is what separated calotype from other early photographic methods and made it the ancestor of modern film photography.

Key Takeaways

  • Calotype uses a paper negative that can produce multiple positive prints, unlike daguerreotypes which create only a single image on metal.
  • The process requires coating paper with silver iodide, exposing it in a camera, and developing it with chemical solutions to create the negative.
  • Calotypes were faster to produce than daguerreotypes and cost less, making photography more accessible in the 1840s and 1850s.
  • The paper negative method used in calotype is the direct ancestor of film-based photography, which dominated until digital cameras became common.

How the Calotype Process Actually Works

The calotype begins with plain writing paper that is brushed with a solution of silver nitrate and potassium iodide. This creates a layer of silver iodide on the paper surface. Before use, the paper is treated again with a solution of silver nitrate and gallic acid — this second coating is called the "gallo-nitrate of silver" and is what makes the paper sensitive to light.

The prepared paper is placed in a camera obscura and exposed to light for anywhere from one to twenty minutes, depending on the brightness of the scene and the sensitivity of the paper. After exposure, the paper is developed by brushing it with more gallic acid and silver nitrate solution, which darkens the exposed areas and creates a visible image. The negative is then fixed with a solution of sodium thiosulfate (also called hypo) to stop further chemical changes.

Once the negative is dry, it can be placed on top of fresh sensitized paper and exposed to sunlight. The light passes through the translucent negative and exposes the paper beneath, creating a positive print. This print is then developed and fixed using the same chemicals. A single calotype negative could produce dozens of prints, though the quality of later prints would gradually decline as the paper negative aged and became less transparent.

Why Calotype Was Faster and Cheaper Than Daguerreotype

Daguerreotypes, which came to market a few years before calotypes, required a polished silver-coated copper plate that was expensive to prepare and could only produce one image. If you wanted a second copy, you had to take another photograph. Calotypes used ordinary paper and common chemicals, making the materials much less costly.

The exposure time for calotypes was also shorter than for daguerreotypes in many cases, especially in bright sunlight. A calotype might take only a few minutes, while a daguerreotype could require ten to thirty minutes or more. This made calotypes more practical for outdoor photography and for photographing people, since subjects had to sit still during the entire exposure.

Because calotypes could be printed multiple times from a single negative, photographers could sell prints to many customers without having to retake the photograph. This economics of reproduction made calotype the preferred method for professional photographers who wanted to build a business, and it is why calotype became more common than daguerreotype in Europe, especially in Britain and France.

The Image Quality Difference Between Calotype and Daguerreotype

Daguerreotypes produced sharper, more detailed images with a wider range of tones. The polished metal surface reflected light in a way that created a mirror-like quality, and the image could be viewed from different angles. Calotypes, by contrast, had a softer, more painterly appearance because the paper fibers diffused light slightly and the image was embedded in the paper rather than sitting on a reflective surface.

This softer quality was actually an advantage for some subjects. Portraits taken with calotype looked less harsh and more flattering than daguerreotypes, which could show every pore and wrinkle with unflinching clarity. Landscape photographers also appreciated the calotype's gentler rendering of detail, which gave their images an artistic quality that appealed to viewers who wanted photographs to look more like paintings.

The paper negative itself was also more fragile than a metal plate. Calotypes could fade over time if not stored carefully, and the paper could tear or become creased. Daguerreotypes, while susceptible to tarnishing, were more durable as physical objects. This durability advantage, combined with the superior sharpness, meant that daguerreotypes were preferred for formal portraiture in the United States, while calotypes dominated in Europe.

How Calotype Led to Modern Film Photography

The calotype's key innovation — using a negative to create multiple positive prints — became the foundation for all film-based photography that followed. When gelatin dry plates were invented in the 1870s, they replaced paper negatives but kept the same principle: expose a light-sensitive layer to create a negative, then use that negative to print positives. When roll film was introduced in the 1880s, the process remained essentially unchanged.

Every photograph taken on film from the 1880s until digital cameras became common in the 2000s followed the calotype model. The negative was the master, and prints were made from it. Professional photographers kept their negatives in archives because they could always make new prints if the originals were damaged or lost. This is why the negative-to-positive workflow became so deeply embedded in photographic practice.

Digital photography broke this chain by eliminating the negative entirely — the image file itself serves as both the negative and the master. But the terminology and thinking patterns from the film era persist. When photographers talk about "shooting" or "capturing" an image, they are using language that comes from the era when you had to physically expose film to light. The calotype, though rarely used after the 1860s, shaped how photography worked for the next 150 years.

Where You Can See Calotypes Today

Calotypes are preserved in museum collections around the world, particularly in Britain, France, and the United States. The Metropolitan Museum of Art in New York, the Getty Museum in Los Angeles, the British Museum in London, and the Musée de l'Orangerie in Paris all hold significant collections. Many of these institutions have digitized their calotypes and made them searchable online, so you can view examples without visiting in person.

Some of the most famous calotypes were taken by William Henry Fox Talbot himself, who photographed his family home, Lacock Abbey, and the English countryside. Other notable calotype photographers include David Octavius Hill and Robert Adamson, who worked in Scotland and created hundreds of portrait calotypes in the 1840s. These images are historically important because they show what early photography looked like and how photographers approached composition and subject matter when exposure times were measured in minutes rather than fractions of a second.

Frequently Asked Questions

How long did it take to make a calotype photograph?

The exposure in the camera took one to twenty minutes depending on light conditions. Development took another thirty minutes to an hour. Printing from the negative took additional time. A single calotype, from start to finish, could take several hours of work spread over multiple days as chemicals dried and solutions were prepared.

Could calotypes be colored?

Calotypes were black and white, but photographers sometimes hand-colored them after printing by explore watercolor or oil paint to the finished print. This was common for portrait calotypes, where adding color to cheeks, lips, and clothing made the image more appealing to customers. The coloring was done by hand and varied in quality depending on the skill of the artist.

Why did calotype disappear if it was so useful?

Calotype was replaced by the wet collodion process in the 1850s, which produced sharper negatives on glass plates and was faster overall. Later, gelatin dry plates and then roll film offered even greater convenience and image quality. By the 1870s, calotype was obsolete for practical photography, though some photographers continued experimenting with it for artistic reasons.

Is calotype the same as salt print photography?

No. Salt print refers to the printing paper used to make the positive print from a calotype negative. The calotype is the entire process and the negative itself. You could make a salt print from a calotype negative, but you could also print a calotype negative onto other types of sensitized paper. Salt printing is one method for creating the final image, not the whole process.

Can you still make calotypes today?

Yes. Some photographers and artists practice historical photographic processes, including calotype, using period-appropriate materials and methods. It is a slow, hands-on process that requires careful chemistry and patience, but the materials are still available. Calotype is sometimes used in fine art photography as a way to explore the history of the medium and create images with a distinctive aesthetic.