TF-4 Alkaline Fixer
TF-4 Alkaline Fixer is Photographer's Formulary's alkaline rapid fixer — non-hardening, ammonium-thiosulfate-based, with the distinguishing alkaline pH (~9) vs the acidic pH of standard F-5/Rapid Fixer. The alkaline character provides two specific advantages: fastest wash times of any commercial fixer (~5-10 min for fiber prints) and compatibility with selenium toning without intermediate steps.
Key features
- Ammonium thiosulfate for fast fixing (1-2 min for film)
- Non-hardening: gelatin remains soft
- Alkaline pH ~9: faster wash than acidic fixers
- Selenium-toner compatible: print can transfer directly to selenium toning bath without intermediate stop or wash
- Liquid concentrate: dilutes 1:3 for film, 1:9 for paper
Workflow
| Material | Dilution | Time |
|---|---|---|
| 35mm/120 film | 1:3 | 1-2 min |
| Fiber paper | 1:9 | 2-3 min total |
| RC paper | 1:9 | 30-60 sec |
Wash times: fiber prints ~5-10 min running water (vs 30+ for F-5).
Practical notes
- Choose TF-4 for archival workflows where minimum-wash-time matters most
- The alkaline pH means no stop bath needed before TF-4 (if developer is alkaline) — though a citric acid stop is still good practice for tray-economy
- Concentrate keeps 1+ year sealed; opened keeps 6 months
- Working solution discards at end of session (typical for rapid fixers)
- Selenium toning workflow: develop → stop → TF-4 → wash 5 min → selenium tone → final wash. The omission of HCA between fixer and selenium tone is the TF-4 workflow advantage.
- PPE: nitrile gloves and eye protection; ammonia smell stronger than acidic alternatives
Related recipes
- [[recipe-rapid-fixer|Rapid Fixer]] — acidic ammonium-thiosulfate alternative
- [[recipe-kodak-fixer-f-5|Kodak Fixer (F-5)]] — slower hardening alternative
- [[recipe-f-24-non-hardening|F-24 Non-Hardening Fixer]] — sodium-thiosulfate non-hardening alternative
- [[recipe-krst|Kodak Rapid Selenium Toner]] — the toner that benefits from TF-4's selenium-compatible workflow
- [[recipe-hypo-clearing-agent|Hypo Clearing Agent]] — wash-aid (less needed with TF-4 than with F-5)
Mixing Instructions
TF-4 is supplied as a liquid concentrate. Dilute according to manufacturer instructions (typically 1:3 with water at 20°C). Stir gently. The solution is ready to use immediately. Working solution keeps 2-3 months. Track capacity by clearing test: place a snippet of unexposed, undeveloped film in the fixer and note the time to clear. When the clearing time exceeds 2 minutes, replace the fixer. TF-4 is alkaline and odorless — no acetic acid smell.
Ingredients for 1L of Concentrate
| # | Chemical | Role | Qty (1L) | Unit | Note |
|---|---|---|---|---|---|
| 1 | Ammonium Thiosulfate | Fixing Agent | 200 | ml | |
| 2 | Sodium Sulfite | Preservative | 15.0 | g | |
| 3 | Sodium Metaborate | Accelerator | 10.0 | g |