Understanding Fabric Types: A Sewer's Essential Guide

Every fabric behaves differently under your sewing machine's needle, and understanding these differences is fundamental to achieving professional results. A machine setting that works perfectly for cotton can cause puckering in silk or skipped stitches in jersey. Learning to recognise fabric types and adjust your approach accordingly is a skill that will serve you throughout your sewing journey.

This guide covers the main fabric categories, their characteristics, and how to set up your machine for success with each type.

The Two Main Categories: Wovens and Knits

All fabrics fall into one of two basic categories based on their construction method:

Woven fabrics are made by interlacing two sets of threads (warp and weft) at right angles. They don't stretch along the straight grain, though they may have some diagonal stretch (on the bias). Examples include cotton broadcloth, linen, denim, silk, and wool suiting.

Knit fabrics are made from loops of yarn that interlock. They stretch naturally, making them comfortable for clothing that needs to move with the body. Examples include jersey, rib knit, interlock, and fleece.

This fundamental difference affects everything from pattern choice to machine settings.

Working with Woven Fabrics

Light to Medium Wovens

This category includes cotton, linen, lightweight wool, and many synthetic blends. These are the most common fabrics for garment sewing and the easiest to work with.

Machine settings:

• Needle: Universal 80/12 for most; Sharp 70/10 for fine fabrics
• Stitch length: 2.5mm for standard seaming
• Thread: All-purpose polyester or cotton
• Tension: Normal (usually around 4-5)

Sheer and Delicate Wovens

Voile, chiffon, organza, and silk charmeuse require extra care. Their lightweight nature makes them prone to puckering and being pulled into the needle plate.

Machine settings:

• Needle: Sharp or Microtex 60/8 or 70/10
• Stitch length: 1.5-2mm (shorter stitches on finer fabric)
• Thread: Fine thread in a matching colour
• Tension: Slightly reduced

Additional techniques:

• Use a straight stitch needle plate if your machine has one
• Place tissue paper under fabric to prevent it being drawn into the machine
• Hold thread tails taut when beginning a seam
• Use French seams to enclose raw edges beautifully

Heavy Wovens

Denim, canvas, upholstery fabric, and heavy wool require more needle penetration power and often benefit from specialised needles.

Machine settings:

• Needle: Denim/Jeans 90/14 or 100/16
• Stitch length: 3-3.5mm
• Thread: Heavy-duty or topstitching thread for visible seams
• Tension: May need slight increase

Additional techniques:

• Sew slowly through multiple layers
• Use a walking foot to prevent layer shift
• Hammer thick seam intersections flat before sewing over them
• Change needles frequently—heavy fabrics dull needles quickly

Working with Knit Fabrics

Knit fabrics present unique challenges because of their inherent stretch. Seams must stretch with the fabric, or they'll pop when the garment is worn.

Light to Medium Knits

Jersey, interlock, and rib knit are common in t-shirts, dresses, and casual wear.

Machine settings:

• Needle: Ballpoint/Jersey 75/11 or 80/12
• Stitch: Stretch stitch, narrow zigzag, or lightning stitch
• Stitch length: 2.5-3mm
• Thread: All-purpose polyester (has some stretch)
• Tension: Slightly reduced

Essential techniques:

• Use a walking foot or engage your machine's dual feed if available
• Don't stretch fabric while sewing (let it feed naturally)
• Stabilise shoulder seams and necklines with clear elastic or twill tape
• Use a twin needle for hems to create a professional stretch hem

Highly Stretchy Knits

Swimwear fabric, activewear materials, and fabrics with high spandex content require special attention.

Machine settings:

• Needle: Stretch 75/11
• Stitch: Lightning stitch or narrow zigzag
• Thread: Polyester or woolly nylon
• Tension: Reduced

Fleece and Sweatshirt Knits

These thick, fuzzy knits are popular for casual wear and blankets.

Machine settings:

• Needle: Ballpoint 90/14
• Stitch: Stretch stitch or zigzag
• Stitch length: 3mm
• Pressure: Reduced presser foot pressure if adjustable

Additional tips:

• Use a walking foot to manage the loft
• Clean your machine frequently—fleece creates significant lint
• Test on scraps first, as seam appearance varies by fleece type

Specialty Fabrics

Velvet and Velour

The pile on these fabrics can shift during sewing, causing layers to "walk" and seams to pucker.

• Use a walking foot—essential for these fabrics
• Pin within seam allowances only (pin marks can show)
• Reduce presser foot pressure
• Consider using a needle appropriate for the base fabric (often a ballpoint for velour, sharp for woven velvet)

Leather, Faux Leather, and Vinyl

These non-fabric materials don't behave like textile fabrics and require specific approaches.

• Use leather needles for real leather (they have a cutting point)
• Use Teflon or roller foot—regular feet stick to these materials
• Never pin through the material (holes are permanent)—use clips instead
• Increase stitch length (2.5-3.5mm)
• Test on scraps—mistakes can't be unpicked cleanly

Lace and Sheer Overlays

When sewing lace:

• Use a fine needle (70/10 or 80/12)
• Reduce tension to prevent distortion
• Consider hand-basting before machine sewing
• Match lace motifs across seams where possible

The Importance of Testing

Regardless of fabric type, always test your settings on a scrap before sewing your project. Use the same number of layers you'll be sewing and evaluate:

• Is the stitch length appropriate?
• Is tension balanced (stitches look the same on both sides)?
• Is there puckering or distortion?
• Does the seam stretch appropriately (for knits)?
• Are stitches skipping?

Adjusting settings on scraps takes minutes; unpicking a garment takes hours. The test swatch is your insurance policy for every project.

Building Your Fabric Confidence

As you gain experience, you'll develop intuition for how different fabrics will behave. Start with straightforward fabrics—cotton broadcloth for wovens, cotton jersey for knits—and gradually challenge yourself with more demanding materials.

Each new fabric type you master expands your creative possibilities. The silk blouse that once seemed intimidating becomes achievable. The swimsuit pattern no longer looks impossible. Understanding fabric is the foundation that makes all sewing projects possible.