Bergger COT 320 – 8×10", 25 Sheets

Bergger COT 320 – Paper for Alternative Photographic Processes, 8 × 10 Inches, 25 Sheets

Bergger COT 320 is a specialist photographic paper made from 100% cotton, developed in France specifically for historical and alternative photographic processes. It is primarily intended for techniques that require the manual application of light-sensitive solutions, such as platinum printing, palladium printing, and iron-based photographic processes.

Unlike general-purpose fine art papers, Bergger COT 320 has been designed with the chemical requirements of photographic processes in mind. Its specially prepared surface promotes even coating with sensitizing solutions and helps control their absorption into the paper fibres.

The paper has a weight of 320 gsm, a natural white colour, and contains no optical brightening agents (OBAs). Its subtly satin surface allows sensitizers to be applied using a brush or glass coating rod.

We also use Bergger COT 320 in our own photographic darkroom, primarily for platinum and palladium printing and iron-based processes. Our knowledge of this paper therefore comes not only from the manufacturer's specifications but also from our practical experience.

Properties Important for Alternative Photographic Processes

• 100% cotton – natural fibres provide a durable and strong support for photographic prints.

• 320 gsm paper weight – a substantial, relatively stiff paper with good mechanical strength.

• No optical brightening agents (OBA-free) – natural whiteness without optical brighteners.

• Satin surface – allows even application of sensitizing solutions while supporting fine image detail.

• Appropriate internal and surface sizing – helps prevent excessive absorption of sensitizer into the paper fibres.

• Good wet strength – particularly important for processes involving multiple washing stages.

Applications in Historical Photographic Processes

Bergger COT 320 is particularly suitable for processes in which the chemical composition and surface properties of the paper have a significant influence on the final print.

Platinum and Palladium Printing

Platinum and palladium printing are among the most demanding photographic processes when it comes to paper selection. Factors such as paper composition, sizing, absorbency, and the presence of substances that may interfere with chemical reactions are particularly important. Bergger COT 320 has been developed with these requirements in mind.

Cyanotype

The paper is suitable for cyanotype printing using both analogue and digital negatives. Its prepared surface facilitates even application of the sensitizer, while the substantial paper weight provides good handling characteristics during wet processing.

Van Dyke Brown

Bergger COT 320 can also be used for Van Dyke brown printing, a process based on the light sensitivity of iron and silver compounds. The properties of the paper influence the uniformity of coating, the reproduction of fine image detail, and the washing and fixing stages.

The paper may also be used for other historical photographic processes, including salted paper printing and gum bichromate printing. Depending on the process, additional paper preparation or sizing may be necessary.

8 × 10 Inch Format

The 8 × 10 inch format (20.3 × 25.4 cm) is particularly suitable for contact printing from large-format negatives. The paper can also be used with digital negatives prepared for alternative photographic processes.

Technical Specifications

• Manufacturer: Bergger

• Country of manufacture: France

• Composition: 100% cotton

• Paper weight: 320 gsm

• Colour: Natural white

• Optical brightening agents (OBAs): None

• Surface: Subtly satin

• Sheet size: 8 × 10 inches (20.3 × 25.4 cm)

• Pack size: 25 sheets

• Applications: Platinum printing, palladium printing, cyanotype, Van Dyke brown, and other historical photographic processes