Micratol-1 (Jean Fajot's developer)

About this developer

Mikratol-1 was developed for a specific purpose: to extract the maximum equivalent sensitivity from Mikrat series technical films without enlarging the grain or increasing the contrast beyond what is necessary. There are two ways to use it. The first is to mix stock solutions A and B in equal parts and dilute the resulting mixture with water at a ratio of 1:19; this working solution is used only once. The second, two-stage method is more interesting: the film is first developed in a 1:19 dilution of Solution A—at this stage, development is gentle, with active detail rendering— — and after 7 minutes, solution B is added while continuing to rotate the spiral, and processing continues for another 12–16 minutes. It is during this second stage that the film’s sensitivity increases—while the grain size remains virtually unchanged.

Character

The developer, also known as Jean Fage’s developer, consists of two stock solutions—A (metol) and B (phenidone + hydroquinone + potassium). An important feature: it does not increase the overall contrast of the image—instead, it increases the film’s equivalent sensitivity. It operates in two modes: by mixing A and B in a 1:1 ratio followed by a 1:19 dilution, or by sequential two-stage development (first in the diluted solution A, then with the addition of solution B).

Best films

Mikrat-Isopan (M-300), Mikrat-Ortho (M-200), and similar technical halftone films.

How to Prepare and Use

1. 1Prepare Solution A: Dissolve methanol and anhydrous sodium sulfite in distilled water to a total volume of 1 L.
2. 2Prepare Solution B: Dissolve phenidone, hydroquinone, sodium sulfite, and potassium sulfite in distilled water to a total volume of 1 L.
3. 3Let both reserve solutions settle for at least 24 hours before use.
4. 4Method 1: Mix solutions A and B in a 1:1 ratio, then dilute the resulting mixture with water in a 1:19 ratio (for example, 10 mL each of solutions A and B per 400 mL of water at 20°C); if necessary, add an anti-veiling agent, such as benzotriazole, for old film.
5. 5For Method 1, rotate the spiral 3–5 times per minute; total development time is about 7 minutes (for Mikrat-300: 25 units — 18 min, 50 units — 21 min, agitating 3 turns every 3 min).
6. 6Method 2: Dilute Solution A with water in a 1:19 ratio (about 20 mL of Solution A to 330 mL of water), and develop the film for 7 minutes while stirring continuously.
7. 7While continuing to rotate the spiral, add about 20 ml of Solution B to the tank and continue developing for another 12–16 minutes.