Gum Bichromate: A hand-coated process using gum arabic and light-sensitive dichromate.

Definition and Overview

Gum bichromate printing is a unique and versatile photographic process that involves the use of gum arabic and a light-sensitive dichromate to create beautifully hand-coated prints. The technique allows for the incorporation of various pigments, resulting in rich and vibrant colors, making each print a one-of-a-kind piece of art.

Originating in the 19th century, gum bichromate has a rich history and has captivated photographers and artists alike with its painterly qualities. At its core, gum bichromate printing involves mixing watercolor pigment with a solution of gum arabic and potassium or ammonium dichromate.

This emulsion is then applied to paper or another suitable support using a brush, roller, or even by hand. The coated surface is exposed to UV light through a negative, which hardens the emulsion in proportion to the amount of light received.

The unexposed areas remain water-soluble and are washed away during development, revealing the final image. This process allows for great control over tonal range and color rendition, making it a favorite among alternative process enthusiasts seeking to express their creativity in new ways.

The beauty of gum bichromate lies in its ability to combine photography with painting techniques seamlessly. Artists can experiment with multiple layers of pigment applications, varying exposure times, and even manipulating the emulsion directly on the paper for unique effects.

The final prints often have an ethereal quality that sets them apart from traditional photographic prints, blurring the line between photography and fine art. With practice and experimentation, photographers can achieve stunning results that showcase their artistic vision in ways that traditional printing methods cannot replicate.

A History of the Technique

Gum bichromate printing is a historic photographic process that dates back to the mid-19th century. Its origins can be traced back to the work of French artist Alphonse Poitevin, who developed the gum bichromate process in 1855 as a way to create colour images from black and white photographs.

Poitevin's innovative technique involved coating paper with a mixture of gum arabic and potassium dichromate, which when exposed to light, hardened the gum arabic in proportion to the amount of light it received. This allowed for a selective hardening of the gum arabic layer, creating an image that could then be brushed with watercolor pigments for colorization.

The gum bichromate process gained popularity among pictorialist photographers in the late 19th and early 20th centuries due to its ability to produce painterly and expressive prints. Artists like Robert Demachy and Alvin Langdon Coburn embraced this method as a way to elevate their photographic work into the realm of fine art.

The soft focus and dreamlike quality achieved through gum bichromate printing made it particularly well-suited for creating ethereal landscapes, delicate portraits, and poetic still lifes. Despite advancements in photographic technology over the years, contemporary artists continue to explore and experiment with this historic process as a means of infusing their images with a timeless aesthetic beauty reminiscent of early photographic masterpieces.

Materials Needed

When embarking on a gum bichromate printing project, it is essential to gather the necessary materials to ensure a successful outcome. The primary ingredient for this process is gum arabic, a natural resin obtained from the acacia tree that serves as the binder for the light-sensitive dichromate solution. Gum arabic can typically be found in art supply stores or online retailers specializing in alternative photographic processes.

Additionally, you will need a source of dichromate, such as potassium or ammonium dichromate, which reacts with light to harden the emulsion and create the final image. In addition to these core ingredients, you will require high-quality watercolour pigments to add colour to your prints.

It is recommended to choose pigments that are transparent and lightfast for optimal results. Other essential materials include brushes for coating the paper with the emulsion mixture, a UV light source for exposing your prints, and trays for washing and processing your images.

Investing in precision measuring tools like graduated cylinders and pipettes will help ensure accuracy when mixing your solutions. Having a flat surface for drying your prints and archival quality paper for creating lasting artworks are crucial components of your gum bichromate printing setup.

Step by Step Guide

To begin the gum bichromate process, gather all the necessary materials: gum arabic, potassium or ammonium dichromate, pigments for coloring, brushes for coating, a light-sensitive paper or fabric to apply the emulsion onto, and a UV light source. The first step involves creating the emulsion by mixing gum arabic with a solution of water and dichromate.

The ratio of these components will vary depending on the desired contrast and colour intensity in the final print—experimentation and practice are key to finding the right balance. Once the emulsion is prepared, it must be quickly applied to the paper or fabric using a brush or another coating tool.

The thickness of the emulsion layer will affect the final result—the thicker it is applied, the more pigment it can hold and thus produce a deeper colour saturation. After applying the emulsion evenly across your chosen substrate, allow it to dry completely in a dark environment to avoid premature exposure.

Once dry, place your negative or image transparency on top of the coated surface and secure them together under a piece of glass to ensure contact. Expose this setup to UV light for a calculated amount of time based on your materials and desired effect—this step is crucial in determining contrast and detail in the final print.

Finishing Touches and Preservation

After completing the gum bichromate printing process, it is essential to pay attention to the finishing touches and preservation of your artwork. This step ensures that your print remains in optimal condition for years to come. To begin with, gently rinse the print in cool water to remove any excess gum arabic solution and dichromate residues.

Take care not to rub or scrub the print vigorously during this process, as it may damage the delicate layers. Once rinsed, allow the print to air dry naturally in a dark room away from direct sunlight.

It is crucial to protect the print from any harsh light exposure during this drying phase to prevent premature fading or discoloration. Additionally, consider placing a protective sheet of glass or plastic over the dried print when storing or displaying it to shield it from dust, moisture, and physical damage.

By taking these precautions during the finishing touches stage, you can prolong the lifespan and aesthetic appeal of your gum bichromate print for future enjoyment and admiration. Preservation plays a key role in maintaining the quality and longevity of your gum bichromate prints.

Store your finished prints flat between acid-free sheets of paper or within archival sleeves designed specifically for artwork protection. Avoid using materials such as PVC plastic that emit harmful gases and can cause deterioration over time.

When framing your prints for display, opt for UV-resistant glass or acrylic to shield them from harmful ultraviolet rays that can cause fading and yellowing. By investing in proper storage solutions and display techniques, you can ensure that your gum bichromate prints remain vibrant and pristine for generations to come.

Tips and Tricks for Success

When embarking on the intricate process of Gum Bichromate printing, there are several tips and tricks that can significantly enhance your success rate. Firstly, it is crucial to pay close attention to the consistency of your gum arabic mixture. Achieving the right balance between gum arabic and pigment is essential for obtaining optimal results in this technique.

Experimenting with different ratios and observing how they affect the final print can help you refine your approach over time. Another key tip for success in Gum Bichromate printing is to carefully choose your light-sensitive dichromate emulsion.

The quality and sensitivity of the emulsion play a vital role in determining the contrast and tonal range of your prints. Investing in a high-quality emulsion will yield more consistent results and allow for greater control over the final outcome.

Additionally, consider experimenting with different exposure times and light sources to see how they influence the development of your prints. By honing these variables through trial and error, you can unlock new creative possibilities in your Gum Bichromate work.undefined

Creative Applications

Creative Applications Gum bichromate printing offers a wide range of creative applications that allow artists to experiment and push the boundaries of traditional photography. One unique application is combining gum bichromate with other alternative printing processes, such as cyanotype or platinum-palladium printing.

By layering different processes, artists can create multi-dimensional and visually striking images that evoke a sense of timelessness and artistry. The combination of gum bichromate with these alternative processes adds depth and complexity to the final print, resulting in truly unique pieces that stand out in the world of fine art photography.

Another creative application of gum bichromate is using it as a medium for hand-coloring photographs. Artists can selectively apply pigment to the emulsion before exposing it to light, allowing for intricate and personalized colorization of black-and-white images.

This process gives photographers full control over the tonal qualities and mood of their prints, enabling them to create custom-tailored artworks that convey specific emotions or narratives. Hand-coloring with gum bichromate adds an element of craftsmanship and individuality to photographic prints, making each piece truly one-of-a-kind and imbued with the artist's personal touch.

Popular Artists Known for Their Work

One prominent artist known for their exceptional work in Gum Bichromate is Alphonse Mucha, a Czech painter and decorative artist who was a leading figure of the Art Nouveau movement. Mucha's intricate and ethereal style translated beautifully into the Gum Bichromate process, allowing him to create mesmerizing and highly detailed prints that captured the essence of his iconic artworks.

His use of soft colors and flowing lines, characteristic of Art Nouveau, lent themselves well to the dreamy quality achievable with Gum Bichromate printing. Mucha's works in this medium often feature elegant figures and intricate floral motifs, showcasing the versatility and delicacy that can be achieved through this hand-coated process.

Another artist celebrated for their mastery of Gum Bichromate is Robert Demachy, a French Pictorialist photographer known for his soft-focus, painterly images. Demachy embraced the creative possibilities offered by Gum Bichromate to further blur the line between photography and painting in his works.

His prints often exhibit a timeless quality, with rich tonality and a sense of depth that adds an almost mystical aura to his subjects. Demachy's experimentation with various techniques within Gum Bichromate printing helped elevate his photography to an art form that transcended mere reproduction, embodying emotion and artistic expression in each print.

Resources for Further Learning and Inspiration

For those looking to delve deeper into the art and technique of Gum Bichromate printing, there are several invaluable resources available that provide further learning and inspiration. One such resource is "Gum Printing: A Step-by-Step Manual Highlighting Artists and Their Creative Practice" by Christina Z. Anderson.

This comprehensive book not only guides readers through the step-by-step process of creating Gum Bichromate prints but also offers insights into how contemporary artists approach and experiment with this historic technique. Anderson's book serves as a practical guide for beginners while also inspiring seasoned practitioners to push the boundaries of their creative expression.

In addition to books, online forums and communities dedicated to alternative photographic processes can be excellent sources of support, knowledge-sharing, and inspiration for Gum Bichromate enthusiasts. Websites like provide a wealth of information on various alternative processes, including Gum Bichromate printing.

Engaging with these online platforms allows artists to connect with like-minded individuals, seek advice on troubleshooting technical challenges, explore new ideas for experimentation, and stay updated on upcoming workshops or exhibitions related to alternative processes like Gum Bichromate printing. The sense of camaraderie and shared passion within these communities can be motivating and enriching for those seeking to expand their skills in this unique art form.


The art of Gum Bichromate truly embodies the essence of handcrafted beauty and creativity. Through the delicate process of coating paper with gum arabic and light-sensitive dichromate, artists are able to create unique and captivating images that showcase a blend of science and artistry. This technique not only allows for endless possibilities in terms of colors, textures, and styles but also encourages artists to experiment and push the boundaries of traditional photography.

As we reflect on the rich history and technical intricacies of Gum Bichromate, it becomes evident that this process is more than just a method; it is a form of expression that speaks to the soul. The tactile nature of working with gum arabic and dichromate fosters a deep connection between the artist and their creation, resulting in images that are imbued with a sense of intimacy and personal touch.

By mastering this time-honored technique, photographers can unlock a world of artistic potential that transcends mere pixels on a screen or prints from digital files. In today's fast-paced digital world where instant gratification often takes precedence, embracing the slow and deliberate process of Gum Bichromate serves as a refreshing reminder to savor each moment spent creating something truly unique.

So, let us continue to explore the boundless creativity that Gum Bichromate offers, inspiring us to infuse our work with passion, depth, and meaning. In a world where mass production reigns supreme, let us revel in the joy of handcrafting our vision onto paper through this timeless photographic process.

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