Hair thread (often called weaving thread) is a strong sewing thread used to attach weft extensions to braids, cornrows, wigs, or caps. It’s designed to be durable, low‑fray, and smooth through hair and wefts.

• Common materials: High‑strength polyester or bonded nylon.
• Typical sizes: You’ll see labels like 210D/3 and #69/T70, indicating a medium‑heavy, tough thread that’s still easy to stitch.
• Colors: Usually black, brown, dark brown, beige, and other neutrals for discreet blending.
• Lengths: Small spools for a project or large cones (hundreds to 1,000+ yards) for multiple installs.
• Tools: Commonly used with curved weaving needles; some options also work in sewing machines.

It’s similar to upholstery‑grade thread, which helps it hold up during wear.

You’ve got a few options, and the best fit depends on your technique and look.

• Bonded nylon: Very strong with a coating that helps reduce fraying and tangles. Often labeled #69/T70 or 210D/3.
• High‑strength polyester: Durable with low stretch; suitable for long wear and everyday installs.
• Monofilament (clear): Nearly invisible for a discreet look, though it can feel slick; often used selectively.
• Cotton: Softer and easy to handle, typically better for light decorative work than long‑term sew‑ins.
• Elastic thread: Useful for decorative wraps or temporary accents, not commonly used for securing full wefts.

Match color to your roots or wefts and choose strength that aligns with your style and maintenance plans.

Many sew‑ins use medium‑heavy thread labeled #69/T70 or 210D/3, which balances strength with ease of stitching. However, the right size can vary by weft type and technique.

• For standard wefts: T70/#69 (210D/3) is commonly chosen for durability.
• For delicate lace or finer work: Slimmer nylon (e.g., around 0.2 mm) may feel less bulky.
• For heavy bundles or thicker tracks: A robust bonded option helps reduce breakage.

Consider your needle size, stitch density, and how snug you tie knots. If you’re unsure, starting with a widely used medium‑heavy size and testing on a scrap weft can help you dial in comfort and hold.

Some weaving threads can be used on sewing machines, especially those labeled for machine use or heavy‑duty sewing. Results can vary by machine and thread size.

• Needle choice: A heavy‑duty or denim needle often handles #69/T70 and 210D/3 threads better.
• Settings: You may need to adjust tension and lengthen stitches slightly; test on a scrap first.
• Spool setup: Large cones may need a thread stand for smooth feeding.
• Speed: Slower, steady stitching can reduce skipped stitches and fray.

Always consult your machine’s manual for thread/needle compatibility. For hand‑sewn wefts, a curved weaving needle remains a popular choice.

It depends on your head size, number of tracks, stitch density, and whether you’re doing a partial or full install.

• Single project: A smaller spool (for example, tens to a few hundred yards) may be sufficient for a basic sew‑in.
• Multiple installs or wig making: Larger cones (hundreds to 1,000+ yards) are practical and cost‑effective over time.
• Plan for extras: Closures, tighter stitch patterns, or double‑wefting can use more thread.

Checking the yardage listed on the product page and accounting for a little extra for knots and touch‑ups can help you avoid running short.