Four numbers and a decision
A grid on a printed board is settled by four numbers: how many rows, how many columns, how much space between the cells, and how much space round the outside. The cell size is not a fifth number — it is whatever is left once the other four are taken out of the board, which is why changing the board size changes the cells and never the spacing.
- Rows and columns. Up to forty of each. The generator warns rather than guesses when the numbers leave no room inside the margin.
- The gap. Entered in the board’s own unit, so a centimetre is a centimetre on the paper whatever the DPI happens to be.
- The edge margin. Larger than the gap, nearly always. It is also the only guide this board draws for the edge of the paper.
- What happens inside a cell. Trim to fill, or keep the whole photograph and let the cell show around it.
Why it hands you loose frames
A run replaces what is on the board and counts as one step, so undo puts the old arrangement back in one keystroke. What it leaves behind is not a grid: it is a set of frames that happen to be in rows. Nothing is attached to a cell, nothing renumbers when you delete one, and pulling the third photograph out to sit at an angle across two rows leaves a gap exactly where it was — which is usually the interesting thing to do with a grid.
That also means the generator is a starting point rather than a commitment. Run it, look at it, undo it, change the columns, run it again. It costs nothing.
Even spacing without a generator
For a handful of photographs the generator is overkill. Select them, line their top edges up with one button, then even out the horizontal gaps with another, and you have a row that is exactly as regular as a generated one. Select in a sweep or with Shift held; both work, and align needs two frames while evening out the gaps needs three.
A generated grid is not a saved arrangement. There is no stored layout to return to, no slot to drop a replacement photograph into, and no template behind any of it — once the cells are frames, the only record of the grid is the frames themselves.
Asked and answered
How do I get a 5 by 5 grid?
Five rows, five columns, and the cell size follows from the board and the two spacing numbers. Twenty-five cells want twenty-five photographs; if the tray holds fewer, the leftover cells simply stay empty and you can fill them later or change the numbers and run it again.
The photographs are different shapes. What happens in a square cell?
One of two things, and you choose which. Fill the cell trims the long sides off each photograph so every cell is completely covered and the grid is perfectly even — the usual answer for a wall of faces. Show the whole photograph keeps every pixel and lets the cell breathe around it, so a mixed portrait-and-landscape set comes out ragged on purpose.
Can I change which photograph is in which cell?
Drag one cell onto another and they trade places. That only happens between frames of the same size and the same angle, which after a run is every pair of them, so the gesture never fires by accident once you have started moving things freely.
Is the grid locked once it is laid out?
No, and that is the point of it. Every cell becomes an ordinary frame the moment it appears: drag it out, turn it four degrees, scale it past its neighbours, send it behind them. Nothing reflows, because there is no grid object left to reflow — only the frames it left behind.
What gap should I use?
For a printed board, a gap somewhere between a third and a half of a centimetre reads as deliberate at arm's length and does not eat the picture. Set the edge margin larger than the gap — twice it is a reasonable start — because a frame that ends exactly at the paper edge looks like a mistake even when it was not.