Converting Hand Loom Weaves to Dobby Loom
Given a hand loom weave with Tie-up, Drafting, and Treadling charts (e.g., 8 shafts, 24 warp ends):
- Open ArahWeave → Weave → Edit to launch the Weave Editor.
- Set dimensions to the Tie-up size (8×8) and 8 shafts.
- Draw/copy the Tie-up into the dobby card.
- Set Warp size to the Drafting size (24), copy Drafting in.
- Rotate 90°.
- Set Warp size to the Treadling size (24), copy Treadling into the Drafting position.
- Save and simulate the fabric.
Progress:
- Identify source weave data: Tie-up, Drafting (threading), Treadling, number of shafts
- Open ArahWeave, go to Weave → Edit to open the Weave Editor
- Change → Dimensions: set weave size = Tie-up size (rows × cols), set number of shafts to match
- Draw the Tie-up pattern directly into the dobby loom card grid
- Change → Dimensions: set Warp size = size of original Drafting (e.g., 24)
- Copy the Drafting from the original hand-loom weave into ArahWeave
- Click the Rotate button in the toolbox (rotates the weave 90°)
- Change → Dimensions: set Warp size = size of original Treadling (e.g., 24)
- Copy the Treadling from the original weave into the Drafting slot in ArahWeave
- Save the card for production
- Run fabric simulation to verify visual correctness
Key conceptual point: in a dobby/ratiera loom, treadling (hand loom) becomes drafting (dobby loom) after a 90° rotation, because dobby cards encode the lifting sequence directly rather than through treadles. The Tie-up defines which shafts the dobby card activates — it maps 1:1 onto the dobby card since both use the same shaft-to-pick logic.
Example 1: Input: Hand loom weave "Twill Thrills" (Weaver's, 2004, p.7) — 8-shaft Tie-up (8×8), Drafting of 24 ends, Treadling of 24 picks. Output: ArahWeave dobby card — weave size 8×8 with 8 shafts loaded from Tie-up; Drafting field populated with the original Treadling (24 picks) rotated 90°; ready-to-save production card with fabric simulation preview.
Example 2: Input: A 4-shaft handloom twill with Tie-up 4×4, Drafting 16 ends, Treadling 16 picks. Output: Dobby card with weave size 4×4, 4 shafts; Drafting field set to 16, populated with original Treadling data rotated 90°; saved as production-ready card.
- Always set dimensions (Change → Dimensions) before pasting data — pasting into a mismatched grid silently truncates or misaligns the pattern.
- Match shaft count exactly to the Tie-up's column count; mismatches cause incorrect lifting plans.
- Verify the rotation direction (90°) visually against the fabric simulation before finalizing — incorrect rotation produces a mirrored or shifted twill line.
- Keep the original hand loom chart open/visible for cross-reference while copying Drafting and Treadling values.
- Use fabric simulation as the final sanity check that the weave structure (e.g., twill diagonal) matches the source pattern.
- Do not confuse Drafting and Treadling slots in the dobby card — on a dobby loom, Treadling becomes Drafting, not the reverse.
- Do not skip the 90° rotation step; dobby cards and hand loom treadling use transposed conventions.
- Do not forget to resize dimensions twice (once for Drafting copy, once for Treadling copy) — reusing the first dimension setting for both will corrupt the second copy.
- Do not assume shaft count equals Tie-up row count without checking — always confirm against the Tie-up chart's actual dimensions.