Flax-Wife's TPI Calculator

Calculate optimal yarn twist based on 1876 linen trade standards

Fiber Specifications

Yarn Grist (Lea)

Lea

1 Lea = 300 yards/lb. Higher Lea means finer yarn.

Intended Usage

High twist for strength and tension resistance.

Twist Multiplier (K)

3.5

Adjust based on desired durability. 3.5 is standard.

Active Ratio

K=3.5 for warp usage

Recommended Twist:

9.0 TPI

Twists per inch required for fiber cohesion

Historical Comparison

Standard #20 Lea: requires ~9.0 TPI
Fine #50 Lea: requires ~14.3 TPI
Fine #100 Lea: requires ~20.2 TPI

Linen requires more twist than cotton due to its length and stiffness.

Spinner's Note: Over-twisting makes yarn wiry. Under-twisting makes it weak.

🎯 A Simple Example: Spinning Warp for a Table Runner

You're spinning a medium-weight linen yarn (#20 Lea) for the warp of a hand-woven table runner. Warp threads need a lot of strength because they are under constant tension on the loom. How many twists per inch should you aim for?

Just do this:

1️⃣ Set "Yarn Grist (Lea)" to 20.

2️⃣ Click the "WARP" preset button.

3️⃣ Notice that the "Twist Multiplier (K)" is automatically set to 4.0.

4️⃣ Look at the "Recommended Twist": it says 10.3 TPI.

5️⃣ Use a twist gauge while spinning to ensure you're hitting roughly 10 twists every inch to prevent your warp from snapping.

Pro tip: If you find the yarn is "kinking" or coiling back on itself too much (pigtailing), try lowering the Twist Multiplier slightly. Flax fibers are stiff and don't need as much twist as wool to hold together!

Data Source: The Linen Trade of Europe (Alex J. Warden, 1876) • Public domain • Solo-developed with AI

Shop Flax Roving

As an Amazon Associate, I earn from qualifying purchases.

Spinning Tools

As an Amazon Associate, I earn from qualifying purchases.

Lab Notes

The Mechanics of Linen: Why Twist Matters

Flax fibers are unique: long and stiff, lacking the natural "crimp" that helps other fibers cling together. This makes the Twist per Inch (TPI) calculation critical for successful spinning.

Why and How This is Useful: Crafting Durable Yarn

This tool allows you to produce linen yarn that is consistent and durable. In 1876, the European linen trade relied on these exact mathematical progressions to ensure industrial looms could run at high speeds without threads snapping. By adjusting the Twist Multiplier (K), you can customize the yarn for its intended use: a high K (around 4.0) for strong warp threads, or a lower K (around 3.0) for softer weft threads.

Historical Context: The Flax-Wife's Wisdom

A "Flax-Wife" or professional spinner had to produce consistent yarn across hundreds of hanks. This tool digitizes that tactile wisdom, allowing modern hobbyists to achieve industrial-grade durability in their hand-spun linen.

🐾 From the Lab Cat's Perspective: Humans make long string for weaving. I make short strings for batting. We all have our priorities. My personal TPI (Tangles Per Inch) when playing with a ball of yarn is remarkably high, often requiring human intervention to resolve. Flax is also much less tasty than wool, which I find to be a significant design flaw. 🐾