What the program actually does

1 · The interlacement editor

The window holds the four regions of a conventional draft and you may work in any of them. A click toggles one square; a drag paints a run; holding Shift while dragging constrains the run to a straight diagonal, which is how a point threading gets turned into a straight draw without counting.

Shaft and treadle counts are not fixed when you start a file. Press ] and the loom grows by one shaft, up to forty; press [ and it shrinks, refusing if a threaded end would be left without a shaft. The maximum repeat is 2048 ends by 2048 picks, which is far past anything a hand loom will hold, and well inside what a draft for a sixteen-block overshot coverlet needs.

Everything recalculates while the mouse is down. On a nine-year-old laptop a full redraw of a 600-end draft takes about 11 ms, so there is no progress bar anywhere in the program.

2 · Working backwards from the cloth

Draw squares straight into the drawdown and Draft tries to find a threading and tie-up that produce them. It groups ends whose interlacement is identical, assigns one shaft per group, and then does the same for picks. If the result needs more shafts than your loom has, the status line says so plainly: needs 11 shafts, loom is set to 8.

Not every pattern is weavable on a shaft loom, and the program will not pretend otherwise. When two ends must behave differently on some picks and identically on others in a way no single threading can satisfy, the offending ends are listed by number and the drawdown keeps your squares, unsolved, until you change them.

3 · Repeats, borders and selvedges

A draft is stored as a unit plus a repeat count, so a 6-end rosepath unit woven 42 times stays a 6-end file. Borders are separate units pinned to the left and right of the warp; they repeat independently and are excluded from the float check only if you ask, because a floating selvedge really does float.

Two selvedge helpers exist: a plain-weave edge that is threaded on the shafts you nominate, and a pair of floating selvedge ends drawn outside the reed plan. Both appear in the printed threading card with their own column so the person at the loom cannot miss them.

4 · Colour and weave

Each warp and weft carries a colour sequence of up to 64 entries, written as a run list: four dark, four light, repeat. The drawdown then paints each square with the warp colour where the end is up and the weft colour where it is down, which is the whole of the colour-and-weave effect. Log cabin, shadow weave and houndstooth are all this one mechanism, and the library shows the first of them.

Colours are flat. There is no yarn texture, no twist and no shading, and that is deliberate: a flat drawdown tells you where the pattern breaks, and only a woven sample tells you how the cloth will feel.

5 · Warnings worth having

Three checks run continuously. The first is the float length: the longest run of picks any single end passes over, and the same for the weft. Anything beyond the limit you set — the default is five — is boxed in the drawdown and listed with its end number.

The second check compares the tie-up with the loom you described in the file: shaft count, treadle count, and whether your loom can sink as well as rise. The third looks at the sett against the reed plan and complains when a dent would take more ends than you allowed, naming the dent.

6 · Paper that survives a workshop

Printing was rebuilt in 3.2 after a weaver told us her threading card ran to nine sheets with the shaft numbers cut off at the fold. A threading card now prints in bands of 100 ends with the end number every tenth column, repeated at both the top and the bottom edge, so a sheet makes sense whichever way it gets clipped to the castle.

The same dialogue writes PDF and SVG. Line weights are specified in millimetres rather than pixels, which means a drawdown exported at 0.25 mm grid lines still reads after a photocopy.

8 · Files, undo and the backup folder

Draft writes one plain-text file per draft, described on the formats page, and never a lock file or a sidecar database. Because the format is text, two versions of a draft can be compared with any diff tool, which is how our own library is maintained.

Undo holds 400 steps and survives a save. Every ninety seconds, if anything has changed, a copy goes into a _flaxforge-backup folder beside your file; ten copies are kept and the oldest is dropped. There is no recovery dialogue on the next launch, because the folder is plainly visible and you can open the copy yourself.

One consequence of plain text: a draft saved by 3.4 opens in 3.0, which reads the header and ignores the keys it does not know. You lose the colour run lists and keep the structure.