Chemigrams — Painting with Photographic Chemistry on Light-Sensitive Paper

Chemigrams are one of the most visually striking and technically fascinating forms of cameraless photography — creating images by applying resists (substances that block photographic chemistry) directly onto photographic paper and then processing the paper through developer and fixer in full room light. The interaction between the resist, the light, the developer, and the fixer produces images of extraordinary complexity: swirling patterns, organic textures, metallic sheens, and colour variations that look like microscopic biology, abstract paintings, or geological cross-sections. Invented by Belgian artist Pierre Cordier in 1956, the chemigram occupies a unique space between photography, painting, and printmaking. This guide covers the process, materials, resist types, techniques, colour paper vs B&W, and creative approaches.

How Chemigrams Work

A chemigram is made by applying a resist substance to photographic paper, then alternately immersing the paper in developer and fixer. Where the resist blocks the chemistry, the paper is protected. Where the resist has cracked, thinned, or been removed, the chemistry reaches the emulsion and produces tonal or colour effects. Developer darkens the exposed silver (the paper is exposed to room light throughout — no enlarger, no camera). Fixer dissolves undeveloped silver, leaving white or clearing the paper. The alternation between developer and fixer, combined with the progressive breakdown of the resist, builds up layers of tone and colour — creating the complex, multilayered imagery characteristic of chemigrams. The process is immediate, hands-on, and endlessly variable.

Essential Materials

You need photographic paper (any type — RC or FB, B&W or colour), standard paper developer (Dektol, Multigrade, or similar), standard fixer, trays for chemistry, and resist materials. Resists can be almost anything that forms a temporary barrier on the paper surface: varnish, nail polish, acrylic medium, petroleum jelly (Vaseline), honey, syrup, wax, rubber cement, masking fluid, egg white, or silicone sealant. Each resist has different adhesion, viscosity, crack patterns, and permeability — producing dramatically different visual results. You also need water trays for rinsing between developer and fixer, and paper towels or sponges. Work in normal room light — chemigrams are a daylight process (the paper is deliberately exposed to light as part of the technique).

The Basic Process

Step one: apply resist to the photographic paper in whatever pattern you choose — brush strokes, drips, stamps, stencils, or finger marks. Step two: immerse the paper in the developer tray. The exposed (unresisted) areas darken. Step three: after a few seconds to a minute, lift the paper and rinse briefly in water. Step four: immerse in the fixer tray. The fixer dissolves and clears the light-struck silver in the unresisted areas. Step five: rinse again. Step six: immerse again in developer (or fixer, or alternate as you choose). Each cycle builds complexity — the resist cracks, lifts, or dissolves progressively, exposing new areas to the chemistry. Continue cycling until the image has the visual complexity you want. Step seven: give a final fix, wash thoroughly, and dry. The entire process can take 10 minutes to an hour depending on how many developer/fixer cycles you perform.

Resist Types and Their Effects

Varnish and nail polish create hard, glossy barriers that crack under the chemistry, producing web-like patterns of fine dark lines over protected light areas. The crack patterns are organic and varied — resembling dried mud, spider webs, or geological fractures. Petroleum jelly (Vaseline) is a soft resist that dissolves gradually in warm chemistry, creating soft-edged, flowing transitions between light and dark areas. Honey and syrup are water-soluble resists that dissolve quickly, producing rapid, dramatic effects — the sugar draws moisture from the developer, creating unique crystal-like patterns before it dissolves completely. Wax (candle wax, encaustic medium) produces a resist that repels aqueous chemistry strongly, creating clean separations with interesting edge effects as the wax chips and peels. Acrylic medium creates a flexible, transparent resist that can be layered — multiple coats produce areas of varying permeability.

Colour Paper Chemigrams

Colour photographic paper (RA-4 or chromogenic paper) produces chemigrams with a stunning range of colours — magentas, cyans, yellows, oranges, and greens — determined by the interaction of the resist with the three colour layers in the emulsion. Different chemistry bath sequences (developer first vs fixer first), different temperatures, and different resist materials produce different colour results on the same paper. The colour in a chemigram arises because each of the three colour layers (cyan, magenta, yellow) responds differently to the processing sequence — partial development, partial fixing, and light exposure create selective colour effects that are unique to each resist and process combination. Colour chemigrams are among the most visually dazzling images in alternative photography.

Creative Techniques

Apply resist with found objects — press bottle caps, forks, combs, corrugated cardboard, or textured fabric into wet resist on the paper surface to create stamped patterns. Use masking tape or stencils cut from card to create geometric resist patterns. Drip liquid resist (thinned varnish, nail polish, or syrup) onto the paper for abstract gestural marks. Paint resist on with brushes for deliberate, controlled compositions. Combine multiple resist types on the same sheet — Vaseline in some areas, varnish in others — to create varying textures and tonalities within one image. Layer multiple chemigram sessions on the same paper — apply fresh resist over previously processed areas and run through the chemistry again for added complexity.

Process Control

While chemigrams are inherently unpredictable, several variables give you control. Temperature: warm developer and fixer react faster and more aggressively, producing stronger tones and faster resist breakdown. Cool chemistry slows the process, giving finer control. Duration: longer immersion in developer produces darker tones; longer in fixer clears more silver. Number of cycles: more developer/fixer cycles build more complexity and tonal range. Developer concentration: dilute developer produces subtle tones; concentrated developer produces strong blacks. The sequence matters: developer first produces a different starting tone than fixer first. Take notes on each piece — resist type, chemistry sequence, temperatures, and cycle counts — so you can reproduce successful approaches.

Finishing and Presentation

After the final fix, wash the chemigram thoroughly (at least 5 minutes for RC paper, 20+ minutes for FB paper) to remove all residual chemistry. Dry flat or hang to dry. Chemigrams on fibre-based paper may curl — flatten under weight overnight. The finished chemigram has a physical presence — the resist residue may add texture and relief to the paper surface. Present chemigrams as original artworks — framed behind glass or mounted on board. Chemigrams can also be scanned at high resolution for reproduction as prints. The metallic sheens, iridescent colours, and three-dimensional textures of chemigrams are best appreciated as original objects — but high-resolution scans capture much of the visual magic for reproduction and exhibition.