Washing and drying prints

Washing removes the fixer left in a print after processing. Fixer that stays behind turns the paper yellow and fades the image, often within a few years.

How long a print needs depends on one thing: what the paper is made of. Resin-coated paper washes in a few minutes. Fibre-based paper takes up to an hour.

Why prints need washing

Fixer dissolves the light-sensitive silver the print no longer needs. It does its job in the tray, but any left in the paper keeps working.

Over time it attacks the silver that forms the image. The first signs are yellow-brown stains in the white areas and highlights that lose their brightness. A properly washed print lasts decades. A poorly washed one can start to stain within a year.

How long does my paper need?

The paper base decides everything about the wash.

Paper	Base	Wash time	Wash aid
Resin-coated (RC)	Paper sealed between two plastic layers	2 to 4 minutes	Not needed
Fibre-based (FB)	Bare paper	30 to 60 minutes	Cuts it to about 20 minutes

RC paper is sealed, so chemistry only ever touches the surface. FB paper has no such barrier, and the fibres soak up fixer like blotting paper. That single difference is why the two need such different treatment.

Wash at around 20°C. Cold water slows washing down considerably. Hot water can soften the emulsion.

Washing resin-coated prints

1. Rinse the print briefly as it leaves the fixer.
2. Wash for 2 to 4 minutes in gently running water.
3. Keep prints separated so water reaches both sides.
4. Squeegee the surface water off before drying.

Do not leave RC prints soaking for long. Water slowly gets in at the edges and can mark or curl the print.

Washing fibre-based prints

Fibre paper can be washed in plain water for 30 to 60 minutes. Using a wash aid is faster, uses far less water, and washes more thoroughly.

Wash aid is sold as hypo clearing agent or archival wash aid. It converts the fixer into compounds that rinse out quickly.

1. Rinse the print for 1 to 2 minutes after fixing.
2. Soak in wash aid for the time on the bottle, usually 5 to 10 minutes, with occasional agitation.
3. Wash for 20 to 30 minutes in running water.

Prints washed in a stack stay contaminated

Water reaches only the edges of a pile. Separate the prints by hand every few minutes, or use a print washer with slots that hold each one apart.

Checking the wash worked

You cannot see residual fixer, which is what makes it dangerous. A residual hypo test kit gives you an answer in a couple of minutes.

Put one drop of test solution on the white border of a washed, still-wet print. Blot it after two minutes and compare the stain against the chart supplied. No stain means the print is clean. A yellow stain means it needs more washing.

Worth doing when you start using a new paper or wash routine, rather than for every print.

Washing colour prints

RA-4 prints use bleach-fix instead of a separate fixer, and the wash is part of the process rather than a step after it. Times are covered in the RA-4 process guide.

Colour paper is resin-coated, so it washes quickly. Wash for the time in the RA-4 process, 1.5 to 3 minutes, handling it like any other RC print.

Drying prints

How you dry a print depends on its paper, the same as washing.

Resin-coated prints

RC paper holds almost no water and dries flat.

• Squeegee both sides on a clean sheet of glass or perspex.
• Hang from a line with clips, or lay on a drying rack.
• Allow 20 to 30 minutes at room temperature.

Warm air speeds drying and does no harm. A hair dryer on its highest setting works well.

Fibre-based prints

Fibre prints curl as they dry, and the thicker the paper the worse it gets. Plan for flattening rather than fighting it.

• Squeegee off the surface water.
• Lay the print face down on a clean mesh drying screen so air reaches both sides.
• Leave for several hours, or overnight for heavier papers.
• Flatten the dry print under a weight, in a press, or between clean board for a day or two.

Dry fibre prints face down. They then curl inward, and a weight flattens them without trouble. Dried face up they curl outward, which is much harder to correct.

Dirty screens and blotters pass fixer to the next print

Wash screens regularly, and replace blotting paper rather than reusing it indefinitely.

Judging a dry print

Black & white prints look slightly darker dry than they do wet, and the difference is enough to matter. Judge exposure from a dry print, never a wet one.

Colour prints shift as they dry too, in a different direction. See how colour prints dry down in the RA-4 process guide.

If a dry print has problems

• Yellow or brown stains in the whites: fixer left in the paper. Wash for longer, or use wash aid on fibre paper.
• A fibre print curls badly: it dried face up. Re-wet it, dry it face down, then flatten it under a weight.
• Stains that match the drying screen: the screen or blotter carried fixer from an earlier print. Wash screens and replace blotters.