Tromp as Writ

Found on the Tools Menu

What It Does

"Tromp as Writ" copies your threading pattern into your treadling — the weft follows the same sequence as the warp. Sometimes this function is called "Weave as Drawn-In". This is a traditional technique where the treadling mirrors the threading, often producing symmetrical, balanced designs. It's commonly used in twill, overshot, and other pattern weaves to quickly generate a treadling that complements the threading.

The name comes from the idea of "tromping" (treading) the treadles in the same order "as writ" (as written) in the threading.

Tromp as Writ (Weave as Drawn-In)

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Opening Tromp as Writ

• Ribbon: Design tab > Tromp as Writ button

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The Tromp as Writ Dialog

When you open Tromp as Writ, you're given three options for what to copy:

Structure Only

Copies the shaft numbers from your threading into the treadling as treadle numbers. For example, if your threading goes 1, 2, 3, 4, 3, 2, your treadling will follow the same sequence: treadle 1, treadle 2, treadle 3, treadle 4, treadle 3, treadle 2.

This does not change any colors — your existing weft colors stay as they are.

Structure and Color

Copies both the threading pattern and the warp colors to the weft. This gives you a draft where the weft sequence and colors exactly mirror the warp. It's useful when you want the finished cloth to look the same in both directions — common in tartan plaids and other symmetric designs.

Color Only

Copies your warp colors to the weft without changing the treadling at all. Use this when you've already set up your treadling the way you want it, but you'd like the weft colors to match the warp — for example, when designing a plaid where the color sequence should be the same in both directions but the structure differs.

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How to Use It

1. Set up your threading the way you want it

2. Go to Design tab > Tromp as Writ

3. Choose your option — Structure Only, Structure and Color, or Color Only

4. Click Apply

Your treadling (and optionally colors) is updated immediately.

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Step-by-Step Example: Creating a Twill Plaid

You've threaded a straight twill on 4 shafts (1, 2, 3, 4, 1, 2, 3, 4...) and you want the treadling to match:

1. Open Tromp as Writ from the Design tab

2. Select Structure and Color (to get matching colors too)

3. Click Apply

Your treadling now mirrors the threading — treadle 1, 2, 3, 4, 1, 2, 3, 4 — and the weft colors match the warp. With a standard twill tie-up, this produces a classic twill plaid.

Step-by-Step Example: Matching Colors for Tartan

You've designed a tartan threading with a specific color sett, and your treadling is already set up with the structure you want. You just need the weft colors to match the warp:

1. Open Tromp as Writ from the Design tab

2. Select Color Only

3. Click Apply

Your weft colors now match the warp sett. The treadling structure is untouched.

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Tips

• Undo works — Ctrl+Z (Cmd+Z) reverts the entire operation in one step.

• Works with liftplan — If your draft is in liftplan mode, Tromp as Writ writes the threading pattern directly into the liftplan (which shafts to raise on each pick) rather than as treadle numbers.

• Treadle count matters — In tie-up mode, the shaft numbers are used as treadle numbers. If your threading uses shaft 6, you'll need at least 6 treadles in your draft. Make sure your treadle count is high enough before applying.

• Great starting point — Many weavers use Tromp as Writ as a starting point, then edit individual picks in the treadling to create variations on the mirrored pattern.

• Overshot and Summer & Winter — These structures often use Tromp as Writ for the pattern treadling, then add tabby picks between the pattern picks using Add Tabby.

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Quick Reference

Option	Threading → Treadling	Colors Copied?
Structure Only	Yes	No
Structure and Color	Yes	Yes (warp → weft)
Color Only	No	Yes (warp → weft)