Keeping the printing session log

Purpose

To leave the darkroom holding the one document a printing map cannot replace: what tonight’s prints were made in, rather than what was done to them. The argument for keeping two records rather than one is on session consistency.

When to use it

Every printing evening. The log is opened before the first sheet goes into the developer and closed before you leave the room.

It is one line per batch, not one line per print. The per-print document is the printing map, which the local-control lab owns, and the two are kept apart because they answer different questions a year later.

Before you start

You should already know why the map alone cannot tell you whether a repeat print is darker because the map is wrong or because this tray is not that tray.

On the bench: the log itself, on paper, open, beside the timer rather than on the dry side of the room; a pencil that works with a wet hand; the fixer’s capacity log; the paper box, with its code visible. This is a Level A record-keeping procedure attached to a Level A session; it adds no chemical handling of its own.

One column decides whether the log is worth keeping, and it is the box code. It is the field that lets a future disagreement be attributed to the paper rather than to you.

Procedure

Opening the line

1. Write the date, the room temperature, and who is printing.
2. Write the paper: maker, product, surface, base, weight and box code, copied off the box rather than remembered.
3. Write the developer: which bottle, its version identifier, its dilution, and the date it was opened.
4. Write the four bath temperatures you read at set-up, the wash included.
5. Write both fixing baths’ running totals as they stand now, and which is bath 1 tonight.
6. Write the filtration and the light source, and note whether the head had its warm-up.
7. Leave a blank column headed sheets, and another headed emergence.

Through the session

8. Number every sheet in the order it is exposed, and write that number on its back in pencil, in the margin, before it goes into the developer.
9. Write the emergence time for sheet one and for every fifth sheet after it.
10. Add each sheet to the fixer’s running total as it leaves the second bath, and count test strips by area rather than ignoring them.
11. Note every change of paper, filter or developer dilution on its own line, with the sheet number it took effect from.
12. Note anything unplanned in the moment it happens: a bath topped up, a tray knocked, a sheet left too long, a light switched on. An event written down is a candidate cause; an event remembered is not.
13. Keep every test strip clipped to the prints it belongs to, with the sheet numbers on both.

Closing the line

14. Read the emergence time of the last sheet and write it beside the first.
15. Total the session’s area and enter it against each bath’s published capacity.
16. Write the wash route by name with its temperature, and the drying method.
17. Write the light the prints were judged under, and whether they were judged wet or dry.
18. Write where each waste stream went, and the date on the fixer rotation if one happened. The route is a local question — see the disposal caveat — and the log records the route you actually took, with the date you last checked it.
19. Write one sentence on what you would change next time. It is the only line you will read first.
20. Close the log in the room, and file the maps with it.

How you know it worked

• Every sheet number on a print’s back has a matching row in the log.
• Two emergence times bracket the session, and the interval between them is visible.
• The area total, not the sheet count, was entered against the capacities.
• Nothing in the log was written after you left the room.
• A stranger reading the log could tell which bath, which box and which evening a given print came from.

If a step fails

Step 2, the box code is not on the box. Then this box is unattributable, and say so in the log in those words rather than leaving the field blank. A blank reads as an oversight; a note reads as a fact.

Step 3, the developer’s version identifier does not exist. Give it one now, by the versioning procedure, and write it on the bottle before the batch. A curve or a print tied to the usual developer cannot be argued with later.

Step 8, a sheet went into the developer unnumbered. Number it as soon as it is fixed, and mark the row numbered late. Do not renumber the sheets around it to make the sequence tidy: the order they were exposed in is the information.

Step 9, the emergence time has grown by half on a sheet you know is correctly exposed. Enter it, and end the bath. That is the cheapest process control in the session and it has just fired.

Step 10, strips were not counted. Count them by area before you close the log, or the capacity column understates the work by a third in a session that made many. Eight narrow strips off a 10-inch sheet are about one 8 × 10.

Step 12, something happened and nobody wrote it down. Write it now, with recalled after the fact against it. A dated recollection is worth more than nothing and less than an observation, and the log should say which it is.

Step 19, you cannot see what to change. Then compare the first sheet with the repeat of it, if you made one; if you did not, that is tonight’s answer, because a session with no repeat cannot separate what drifted from what you decided.

What to record

The line itself, in this order: date; bath temperatures; paper, base and box code; developer, version, dilution and date opened; emergence times; sheets as area against each capacity; both fixers’ running totals; the wash route and its temperature; the drying method; the judging light; where the waste went. Then the sentence at step 19. A log kept as a photograph of a whiteboard is not a log, because the field that will matter is the one that is out of frame.