Fiber-based photographic paper, properly processed and stored, is the most permanent black-and-white print material in common use. Museums, collectors, and serious photographers demand archival processing for work that matters. This guide covers the complete workflow for permanence.
Archival processing isn't difficult—it's thorough. Each step ensures that nothing remains in the print to cause future deterioration.
Active time: 45-60 minutes per print Total time: 2+ hours (including washing and drying)
This guide assumes you've completed:
Why Fiber Paper?
Longevity
Properly processed and stored fiber prints are among the most stable photographic images, which is why museums and archives prefer them.
RC paper comparison: Modern RC prints are stable when well processed, but there is far less long-term evidence for them, so fiber remains the archival standard.
Image Quality
Beyond longevity, fiber paper offers:
- Deeper, richer blacks with more apparent "depth"
- More subtle tonal gradations
- Surface textures that feel substantial
- Better response to toning
- A tactile quality that RC can't match
When to Use Fiber
Use fiber for:
- Exhibition prints
- Portfolio pieces
- Prints for sale
- Any work you want to survive you
- Competition entries requiring archival standards
Use RC for:
- Work prints and proofs
- Learning and testing
- Quick turnaround needs
- Prints that don't require permanence
Beginner's Minimal Workflow
If you don't have a full archival setup yet, you can still make good fiber prints. Here's a simplified workflow that produces long-lasting (though not museum-grade archival) results:
Minimal fiber processing:
- Develop for 90 seconds minimum (don't pull early)
- Stop bath for 10-30 seconds (Ilford gives 10 seconds in Ilfostop 1+19)
- Fix in fresh fixer: Ilford gives 1 minute in Rapid Fixer 1+4 or 2 minutes at 1+9. Fixing for longer makes washing harder
- Wash for 60 minutes in running water (Ilford's figure for double-weight fibre paper) with periodic agitation
- Dry flat on a clean towel or hang by one corner with a clip
What you're missing vs full archival:
- Two-bath fixing (provides more complete silver removal)
- Washing aid (reduces wash time and improves fixer removal)
- Archival print washer (more efficient water circulation)
- Residual fixer testing (confirms washing is complete)
This simplified workflow produces prints that will last decades with reasonable storage. When you're ready to make truly archival prints for exhibition or sale, invest in the full workflow described below.
The single best improvement you can make is adding a washing aid (Ilford Washaid, Kodak Hypo Clearing Agent). It costs little, reduces washing time by two-thirds, and significantly improves print permanence. Add this first, then consider two-bath fixing and an archival washer.
Fiber Paper Handling
Fiber paper behaves differently from RC throughout processing.
Wet Behaviour
Expansion: Fiber paper absorbs water and expands slightly in each dimension. This is normal.
Curl: Wet fiber paper curls dramatically, especially at the edges. Handle gently to avoid creases.
Fragility: Wet emulsion is soft and easily damaged. Never touch the image surface.
Handling Techniques
- Pick up prints by opposite corners, letting the centre bow
- Support large prints with both hands underneath
- Use print tongs with covered tips to avoid scratches
- Never stack wet fiber prints directly on each other
- Transfer carefully between trays without bending
Wet fiber prints scratch easily. A fingernail, rough tong tip, or even another print's corner can permanently mark the emulsion. Handle with care throughout wet processing.
Extended Development
Archival prints require complete development—no shortcuts.
Minimum Development Time
Develop fiber prints for at least 90 seconds at 20°C, regardless of when the image "looks done."
Why extended time matters:
- Ensures complete conversion of exposed silver
- Develops maximum density (Dmax) in blacks
- Builds proper contrast throughout the tonal scale
- Produces more stable silver image structure
Maximum Black Test
Test your development by making a print with a completely black area (an unexposed piece of negative, or the film rebate). Develop for various times and compare the blacks.
If blacks improve with longer development, your standard time is too short.
Developer Recommendations for Archival Work
Use fresh developer at proper concentration:
- Ilford Multigrade: 1+9, 2 minutes (Ilford's range 1½–3 minutes)
- Kodak Dektol: 1+2, typically around 1½-2 minutes; follow Kodak's datasheet for your paper
Higher dilutions (1+14, etc.) require even longer times and may not achieve maximum black.
Two-Bath Fixing
Two-bath fixing is the most economical route to archival fiber prints. A single bath also works if you replace it often: Ilford's limit for maximum permanence is about 10 8×10 prints per litre, or about 40 if you also use a washing aid.
Why Two Baths?
Single-bath fixing problem: As fixer works, it accumulates dissolved silver compounds. These silver-thiosulfate complexes become difficult to wash out and cause eventual staining.
Two-bath solution: The first bath removes most silver halides. The second bath—which stays relatively fresh—completes the job and ensures no silver-thiosulfate complexes remain.
Two-Bath Procedure
Prepare two identical trays of fixer at working dilution (e.g., Ilford Rapid Fixer 1+4).
After stop bath, place print in Fixer Bath 1. Fix with agitation for 1 minute (1½ minutes at 1+9).
Transfer print to Fixer Bath 2. Fix with agitation for 1 minute (1½ minutes at 1+9).
Total fixing time: 2 minutes at 1+4 (1+1), or 3 minutes at 1+9. Don't extend it: longer fixing gives no benefit, makes washing harder and can etch the image.
Bath Rotation
Track how many prints go through each bath:
- When Bath 1 has fixed about 40 8×10 prints per litre (Ilford's 2 g/l silver limit), discard it
- Move Bath 2 to the Bath 1 position
- Mix fresh fixer for new Bath 2
This ensures the second bath is always fresher than the first.
Because Bath 2 only receives prints that have already been mostly fixed, it stays fresh much longer than Bath 1. Ilford suggests repeating the rotation up to four times, then replacing both baths, and replacing both after one week in any case.
Non-Hardening Fixer
For archival work, use non-hardening fixer:
- Standard Ilford Rapid Fixer is non-hardening
- Avoid fixers labelled "with hardener"
- Hardened emulsion releases chemicals more slowly during washing
Hypo Clearing / Washing Aids
Washing aids (also called hypo clearing agents) dramatically reduce the wash time needed to achieve archival permanence.
How They Work
Washing aids convert residual fixer compounds into forms that wash out more easily from paper fibres. They don't remove fixer directly—they make subsequent washing more effective.
Available Products
Ilford Washaid:
- Dilution: 1+4
- Treatment time: 10 minutes
- Followed by a 20-minute wash (5 minutes in Ilford's short-fix optimum-permanence sequence)
Kodak Hypo Clearing Agent:
- Similar protocol
- Available in powder form
Heico Perma Wash:
- Ready-to-use or dilutable
- Similar effectiveness
Washing Aid Procedure
After two-bath fixing, rinse print in running water for 5 minutes (Ilford's figure). This removes surface fixer.
Place print in washing aid solution (properly diluted) for 10 minutes. Agitate occasionally.
Transfer to final wash. Wash in running water for 20 minutes (5 minutes is enough only after Ilford's 1-minute single-bath fix).
Test for residual fixer if permanence is critical (see below).
Without washing aid: Fiber prints require 60 minutes in running water (Ilford's figure for double-weight paper).
With washing aid: About 20 minutes of final washing achieves equivalent or better results.
Besides saving time, washing aids dramatically reduce water consumption. A session of fiber prints uses far less water with proper washing aid treatment.
Archival Washing
The goal: remove all fixer and dissolved silver compounds from the paper fibres.
Water Flow Requirements
Slot washers (archival print washers):
- Best option for fiber paper
- Each print in its own slot with water circulation
- Prints don't touch each other
- Complete water replacement every 5 minutes
- Examples: Versalab, Zone VI, Kostiner
Tray washing:
- Acceptable but less efficient
- Change water completely every 5 minutes
- Don't overload the tray
- Agitate prints and separate them regularly
Running water siphon:
- A siphon in the tray bottom pulls water from below
- Fresh water enters from above
- Creates circulation that removes chemicals
Wash Water Temperature
Keep wash water within a few degrees of processing temperature (18-24°C).
Too cold: Slows fixer release from paper fibres. Too warm: Can soften emulsion excessively. Temperature shock: Large changes cause reticulation (wrinkling of the gelatin layer).
Washing Time Guidelines
| Method | Minimum Wash Time |
|---|---|
| With washing aid (5-minute rinse, 10 minutes in Washaid) | 20 minutes |
| Ilford optimum-permanence sequence (1-minute fix, Washaid) | 5 minutes |
| Without washing aid | 60 minutes |
| Tray instead of slot washer | Longer: change water completely every 5 minutes |
Testing for Residual Fixer
For critical work, don't guess—test.
Kodak HT-2 Test:
- Cut a small strip from the print margin (white border area)
- Apply a drop of HT-2 solution
- Wait 2-3 minutes
- Compare the stain colour to the reference chart
Interpreting results:
- No stain or very faint yellow: Acceptable
- Light yellow: Borderline—wash more
- Orange or brown: Unacceptable—wash significantly more or re-treat with washing aid
Ready-made residual hypo test solutions are sold by darkroom suppliers. If you mix your own, follow the published Kodak HT-2 formula exactly: it is silver nitrate in dilute acetic acid, and any substitution (sulfite, for example) makes the test meaningless. Silver nitrate causes severe eye damage, so wear eye protection.
Apply to margin, compare to control strip.
Test only white margins—the test solution stains the paper. If your print has no margins, sacrifice a test print from the same session.
Drying Fiber Prints
Fiber prints require careful drying to avoid damage and excessive curl.
Screen Drying (Recommended)
Setup:
- Fibreglass window screen or dedicated drying screens
- Clean, dust-free environment
- Good air circulation
Procedure:
- Remove print from wash, let excess water drip off
- Place print face-down on screen (emulsion against screen)
- Allow to air dry completely (4-12 hours depending on humidity)
- Prints will curl toward the emulsion (face) side
Why face-down: Prevents dust settling on the wet emulsion. The screen texture doesn't transfer through the paper base.
Blotter Drying
Setup:
- Clean photographic blotters
- Flat boards for weight
Procedure:
- Drain print and place between blotters
- Add light weight (a board, not heavy books)
- Change blotters after 30-60 minutes as they absorb moisture
- Continue until print is dry (may require several blotter changes)
Advantages: Flatter prints than screen drying. Disadvantages: Blotters can contaminate—use only fresh or properly washed blotters.
Heated Dryers
Not recommended for archival work. Heat accelerates chemical reactions and may affect long-term stability. If you must use heated drying:
- Keep the heat as low as the dryer allows
- Don't ferrotype (chrome-drum glossy finish)—ferrotyping can trap residual chemicals
Drying Time
Don't rush drying. Prints should be completely dry before any further handling:
Drying time depends mainly on humidity and air circulation; allow several hours to overnight.
Test by touching the print back—if it feels cool, there's still moisture evaporating.
Flattening Fiber Prints
Dried fiber prints curl. Flattening is the final step.
Dry Mount Press Method
The standard professional approach:
Warm the dry mount press to the low temperature recommended by its maker (flattening needs far less heat than mounting).
Place print face-up on press bed.
Cover with clean release paper or mount tissue cover sheet.
Close press briefly (typically under a minute).
Remove and place under weight while cooling.
Heat relaxes the fibres; pressure flattens; cooling while weighted sets the flat shape.
Weight Flattening
Without a press:
- Place print between clean archival boards
- Stack multiple prints with boards between each
- Weight heavily (20+ pounds of books or weights)
- Leave for 24-48 hours minimum
Results are acceptable but not as flat as press flattening.
Humidity Re-conditioning
For severely curled prints:
- Place print in a sealed container with a damp (not wet) sponge
- Allow humidity to soften fibres (1-2 hours)
- Remove and immediately flatten under weight or in press
- Dry flat
This is time-consuming but can rescue badly curled prints.
Archival Storage
Processed prints need proper storage to maintain archival permanence.
Interleaving
Always interleave prints with acid-free tissue or glassine:
- Prevents prints from sticking to each other
- Protects emulsion surface from scratches
- Buffers against environmental changes
Archival interleaving materials:
- Acid-free tissue paper
- Archival glassine
- Unbuffered acid-free paper (for some historical processes)
Storage Materials
Boxes: Acid-free archival boxes, drop-front for easy access Folders: Acid-free folders for individual prints Sleeves: Mylar or archival polypropylene for frequently handled prints
Avoid:
- Cardboard or regular paper (acidic)
- Plastic sleeves with PVC
- Rubber bands or paper clips touching prints
Environmental Conditions
Ideal storage:
- Temperature: as cool as practical, since heat speeds deterioration (the Library of Congress gives mould risk above 60% RH with temperatures over 75-80°F)
- Relative humidity: 30-50% (Library of Congress), with 30-40% best if only photographs are stored
- Stable conditions (avoid fluctuation)
- Dark (no prolonged light exposure)
Problematic conditions:
- High humidity (mold, sticking, ferrotyping)
- Low humidity (brittleness, cracking)
- Temperature swings (causes expansion/contraction cycles)
- Light (eventual fading, especially with certain toners)
Poor storage can undo good processing. A print processed to archival standards but stored in a damp attic or sunny room will deteriorate faster than expected.
Complete Archival Workflow Summary
Develop for full time (90-120 seconds minimum) in fresh developer.
Stop for 10-30 seconds in indicator stop bath (Ilford: 10 seconds in Ilfostop 1+19).
Fix in two baths: 1 minute each at 1+4 (1½ minutes at 1+9), non-hardening fixer.
Rinse for 5 minutes in running water.
Washing aid treatment for 10 minutes.
Final wash for 20 minutes in archival washer or with complete water changes.
Test margin for residual fixer (for critical prints).
Dry on screens face-down, or between blotters.
Flatten in dry mount press or under weights.
Store interleaved in acid-free materials, stable environment.
Summary
- Fiber paper is the archival standard when properly processed and stored
- Two-bath fixing (or a single bath replaced often) keeps residual silver low enough for archival permanence
- Washing aids reduce wash time from 60 minutes to about 20 minutes
- Test for residual fixer on critical prints
- Handle wet fiber paper carefully—emulsion scratches easily
- Dry slowly on screens or in blotters
- Flatten with heat and pressure for professional results
- Store in acid-free materials at stable temperature and humidity
Archival processing requires attention to every step, but the result is a print that will outlast you and potentially your grandchildren. For work that matters, there's no substitute.
Sources
- Processing and finishing ILFORD fibre base papers (fact sheet)
- ILFORD optimum permanence wash sequence for FB papers, Ilford/Harman
- ILFORD Rapid Fixer technical information, Ilford/Harman
- MULTIGRADE FB Classic technical information, Ilford/Harman
- Care, handling and storage of photographs, Library of Congress