Meg Turner

Printmaker and photographer working out of New Orleans, Louisiana. Her practice spans prints, photography, and installation projects that respond to the landscape and the community she is part of.

In addition to her own work and contract printing, Meg serves as the master printer for local photogravure and wet collodion artist Josephine Sacabo. She founded the New Orleans Community Printshop and has since stepped back from a leadership position to focus on her studio practice.

She shoots primarily with a 4×5 Crown Graphic press camera, working in film and wet collodion.

A circular portrait embedded in a dramatic magenta-to-indigo gradient field, with deep black edges framing the composition

The Chemistry Of Fixer And How To Test Its Strength

Fixer is the stage that makes a photographic image permanent. In black-and-white film, paper, and many traditional printing processes, it removes the light-sensitive silver halides that remain after development. Without adequate fixing, an image may look finished at first but gradually stain, fade, or discolour when exposed to light.

For artists working across darkrooms, wet collodion, and hand-made prints, fixer is less mysterious when treated as a working chemical rather than a background liquid. Its useful life can be measured, recorded, and managed. That matters in a shared studio in Melbourne, a community darkroom in Sydney, or a small home workspace where chemical waste, water temperature, and ventilation all affect the result.

What Fixer Does To Silver Halides

Unexposed silver halide crystals are present in photographic emulsion after development. Fixer dissolves and carries them away by forming soluble silver-thiosulfate complexes. The active ingredient is usually sodium thiosulfate in traditional hypo, or ammonium thiosulfate in rapid fixer. Ammonium formulations generally clear film and paper faster, while sodium thiosulfate is often associated with longer fixing times.

The reaction is progressive rather than instant. At first, thiosulfate has plenty of capacity to bind silver. As more film or paper passes through the bath, dissolved silver accumulates and the fixer becomes less effective. Exhausted solution can still appear clear and may still produce an apparently acceptable print, which is why appearance alone is a poor test of fixer strength.

Fixer performance depends on concentration, temperature, agitation, dilution, pH, and the emulsion being processed. A film fixer and a fibre-based paper fixer may have different recommended capacities. Fixing paper for too long in a highly active bath can increase washing demands, while insufficient fixing leaves residual silver compounds embedded in the image material.

Why Fixer Loses Capacity

Every sheet of photographic paper and every length of film consumes some fixing capacity. Dense negatives and large dark areas on prints contain more silver that must be removed. A busy print session can therefore exhaust fixer more quickly than a quiet session using pale contact prints, even when the same volume of solution is used.

Dilution is another source of uncertainty. Manufacturers normally specify a working strength, such as a concentrate mixed with water at a particular ratio. Reusing a bath after substantial evaporation can make the chemistry more concentrated, but that does not restore its capacity. Conversely, adding too much water reduces the amount of active thiosulfate and lengthens clearing time.

Temperature is especially relevant across Australia. A darkroom in Brisbane may run warmer than one in Hobart, while winter conditions in Canberra can make a working bath noticeably colder. Keep chemistry within the manufacturer’s recommended range and measure the temperature rather than relying on how the tray feels. Consistent conditions make test results far easier to interpret.

Practical Ways To Test Fixer Strength

The simplest working test is the film clearing test. Place a small piece of unexposed but processed film into the fixer and record how long it takes to become clear. Compare that time with fresh fixer under the same temperature and agitation conditions. Many printers use a fixing time of roughly twice the clearing time, but the product data sheet and the emulsion manufacturer’s advice should take priority.

A hypo test solution, often called a fixer exhaustion test, can indicate whether silver has accumulated beyond a useful level. A drop is placed on a sample of used fixer, and the colour change is compared with the product’s chart. This is a quick screening method, although it does not measure every factor that affects archival permanence. It is best used alongside capacity records and clearing-time tests.

Silver-estimation test papers or electronic silver monitors provide a more specific indication of dissolved silver. These are useful in a production darkroom where fixer is reused frequently or where many artists share one processing area. A small labelled sample can also be sent to a photographic chemistry supplier or environmental testing service when accurate silver concentration data is needed.

Good records turn testing into a repeatable studio habit. Note the date, dilution, volume, temperature, type of material processed, and approximate surface area or film length. When documenting any repeatable process, a concise process reference can illustrate the value of recording each step clearly, even though the chemistry itself should always be governed by photographic product instructions.

Safe Handling And Responsible Disposal

Fixer is less hazardous than developer or stop bath in many ordinary darkroom setups, but used fixer contains dissolved silver and should not be treated as harmless wastewater. Silver can interfere with aquatic systems and may be regulated as a contaminant. Do not pour exhausted fixer into a garden, stormwater drain, or household sink simply because the liquid looks clean.

In Australia, chemical storage and disposal should be managed under the relevant state or territory Work Health and Safety requirements. Keep the original label or a current safety data sheet, use gloves and eye protection, and store concentrates in sealed, clearly labelled containers away from incompatible chemicals. Local council rules, trade-waste requirements, and state environmental agencies may apply to disposal, particularly for studios, schools, and businesses.

Silver recovery is a practical option. Used fixer can be collected for a recovery cartridge, metallic replacement system, or specialist waste contractor. Some community darkrooms and commercial photographic laboratories arrange collection through chemical recyclers. This is particularly useful in Sydney and Melbourne, where shared studios may generate enough volume to justify a formal recovery service.

Adequate ventilation, splash control, and separate measuring equipment reduce mistakes. Never return contaminated fixer to a fresh stock bottle. Keep fixer trays clearly identified, and wash measuring cylinders before using them for another chemical. Traditional printmaking studios often handle several materials in close quarters, so simple labelling prevents accidental mixing.

Building A Reliable Darkroom Routine

Test fresh working fixer before an important edition, exhibition print, or irreplaceable negative. Establish its normal clearing time, then repeat the test as the bath is used. When the clearing time lengthens significantly, or when the fixer reaches its stated capacity, retire it rather than trying to extend its life with extra time.

Fibre-based paper deserves particular care because retained fixer can cause yellowing and staining over time. Adequate fixing must be followed by a thorough wash, often with a suitable wash aid where recommended. Resin-coated paper usually washes more quickly, but its shorter wash requirement does not remove the need for correctly functioning fixer.

Shared darkrooms benefit from a written capacity policy. A tray can be marked with the date mixed, dilution, and material processed. A community printshop may need separate limits for film, resin-coated paper, and fibre paper, because treating all materials as equivalent can lead to premature exhaustion or unnecessary chemical waste. Artists working with collaborators can also compare notes with other printmakers, including practices documented by B H Clay Smith.

A dependable fixer routine protects negatives, editions, and the working environment at the same time. Test the bath before major work, document the result in the studio log, and arrange responsible recovery for used solution. Explore Meg Turner’s printmaking and photographic practice for further context on hands-on processes, traditional darkroom methods, and the care behind each finished image.