Mastering Techniques for Sewing Ultralight Apparel Fabrics

Ultralight outerwear fabrics are characterized by their lightweight construction and often have properties such as breathability, water resistance, and packability. Here's a comparison of common types of ultralight fabrics:

Breathable Windshell Fabrics:

• Ideal for lightweight wind-resistant outerwear layers.
• Varying deniers and finishes offer different levels of durability and breathability.
• Durable Water Repellent (DWR) finishes shed light precipitation
• Options include Ripstop Nylon, AIRWAVE™ Hybrid Ripstop Nylon, HyperD™, and MEMBRANE 10.

Waterproof Rain Jacket Fabrics:

• Designed to provide waterproof protection in wet conditions.
• Coated or laminated finishes provide water resistance with limited to no breathability.
• While not 100% waterproof, when properly seam sealed, garments are highly water resistant.
• Options include Polartec Neoshell, Silpoly, and Silnylon.

When selecting fabric, say for your UL Windshell pattern, it's important to consider factors such as durability, sewability, and performance to ensure the best outcome for your project. Let's compare the recommended fabrics for both breathable windshell and water-resistant rain jacket variants:

Breathable Windshell Fabrics:

1.9 oz Ripstop Nylon
Durability: Offers good durability due to its higher denier (70D). Sewability: Relatively easy to sew with standard sewing equipment. Performance: Provides breathability with a durable water repellent (DWR) finish. Choose uncalendered variants for most breathability.
1.8 oz AIRWAVE™ Hybrid Ripstop Nylon
Durability: Slightly lower denier (40D) but still offers decent durability. Sewability: Air Textured Yard treatment has a cotton-like feel and its easy to sew with standard equipment. Performance: Offers breathability and light water resistance with a DWR finish, suitable for lightweight windshells.
1.1 oz Ripstop Nylon
Durability: Lower denier (20D) fabric results in ultralight, packable jackets with lower durability compared to higher denier options. Sewability: Requires more care when sewing due to its lightweight nature, but manageable with proper techniques. Performance: Provides high breathability with uncalendered options. Calendered variants are down-proof but less breathable, suitable for ultralight windshells.
1.0 oz HyperD™
Durability: Similar to 1.1 oz Ripstop Nylon, yet much softer to touch. Won't feel clammy. Sewability: Comparable to Ripstop Nylon. Frays faster so minimize handling. Manageable with proper techniques. Performance: Highest breathability and windshell performance, but durability suffers. Highly susceptible to abrasion damage, snags and pulls.
0.66 oz MEMBRANE 10 Taffeta Nylon
Durability: Lower denier (10D) may compromise durability, especially in high-wear areas. Sewability: Requires delicate handling due to its extremely lightweight nature. Performance: Provides moderate breathability with a calendered finish and DWR, ideal for super ultra-lightweight windshells.

Waterproof Rain Jacket Fabrics:

Polartec Neoshell
Durability: Offers excellent durability with multiple weights and styles available. Sewability: May require specialized techniques and equipment due to its waterproof membrane construction. Performance: Provides waterproof breathability similar to GoreTex, suitable for high-performance rain jackets.
1.6 oz Silpoly
Durability: Offers good durability with a silicone/PU mix coating on both sides. Sewability: Relatively easy to sew with standard equipment, but slippery to handle. Performance: Provides water resistance with a silicone/PU coating, suitable for lightweight packable rain jackets.
1.1 oz Silnylon
Durability: Similar to Silpoly, offers good durability with a Sil/PU coating on both sides. Sewability: May require more care when sewing due to its lightweight, slippery nature but manageable with proper techniques. Performance: Provides water resistance with a silicone/PU coating, suitable for ultralight packable rain jackets.

When choosing the fabric for your ultralight gear, consider your specific needs and preferences in terms of weight, durability, and performance to ensure the best results for your project.

Seam sealing is recommended for waterproof garments such as rain jackets. However, for breathable windshell fabrics, which prioritize wind resistance and breathability over waterproofing, seam sealing may not be necessary or practical. These fabrics are designed to shed light moisture and maintain breathability, and sealing the seams is generally not recommended.

Taping Waterproof Breathable (WPB) Fabrics:

Seam taping is essential for maintaining the waterproof integrity of WPB fabrics such as Neoshell by sealing the seams to prevent water penetration. Seam tape is not compatible with Sil/PU impregnated fabrics like Silnylon. Fabric-specific waterproof seam tape is applied to the inside of seams using heat and pressure to create a waterproof barrier. Proper seam tape application is critical to maintaining waterproofness, so follow manufacturer instructions carefully and use appropriate equipment for best results.

Seam Sealing Silicone-Coated Fabrics

Seam sealing is necessary for waterproofing silicone-coated fabrics, as the silicone coating alone may not fully seal seams. Liquid silicone sealant is applied to the seams using a brush or applicator, creating a waterproof barrier that adheres to the fabric. Proper seam sealing technique is essential for effective waterproofing, so ensure seams are clean, dry, and free from contaminants before applying sealant.

MELCO™ Seam Tape for WPB Fabrics
GEAR AID Seam Grip for Siicone-Coated Fabrics

Breathable Windshell Fabrics

Fusible Interfacing:

• Usage: Fusible interfacing is commonly used with apparel fabrics to add structure and stability to areas such as pockets, cuffs, and buttonholes.
• Application: It is applied to the wrong side of the fabric using heat from an iron, creating a bond between the interfacing and fabric.
• Benefits: Provides a crisp finish and helps maintain the shape of garment components without adding bulk.
• Considerations: Select a fusible interfacing appropriate for lightweight fabrics to ensure compatibility and prevent heat deformation or melting.

Sewable Interfacing:

• Usage: Sewable interfacing can also be used with ultralight fabrics which can't tolerate heat from an iron to add reinforcement to seams and areas requiring additional support.
• Application: Sewn directly onto the fabric using standard sewing techniques, allowing for greater control over placement and application.
• Benefits: Offers flexibility and ease of handling during construction, particularly for curved or intricate areas.
• Considerations: Choose a sewable interfacing that complements the weight and characteristics of the fabric for optimal results.

Waterproof Rain Jacket Fabrics

Fusible Interfacing:

• Usage: Fusible interfacing is less commonly used with waterproof fabrics due to the risk of compromising the fabric's water-resistant properties.
• Application: If used, apply fusible interfacing sparingly and with caution, focusing on non-critical areas where water resistance is not a primary concern.
• Benefits: Provides added stability and structure to selected areas without the need for stitching, contributing to a cleaner finish.
• Considerations: Test fusible interfacing on a scrap piece of fabric before applying to the main garment to ensure compatibility and minimal impact on water resistance.

Sewable Interfacing:

• Usage: Sewable interfacing is preferred for waterproof fabrics to maintain their water-resistant properties and prevent compromising seam integrity.
• Application: Sewn directly onto the fabric using standard sewing techniques, allowing for reinforcement of critical seams and areas requiring additional support.
• Benefits: Ensures seam integrity and waterproofing by maintaining the fabric's original properties and preventing water penetration through stitch holes.
• Considerations: Choose a sewable interfacing specifically designed for use with waterproof fabrics and follow manufacturer recommendations for application and seam reinforcement.

2-Way Stretch Tricot Fusible Interfacing for Apparel Fabrics
Lightweight Non-Woven Fusible Interfacing for Apparel Fabrics
Sew-In Non-Woven Lightweight Interfacing for Apparel Fabrics

Now that you're familiar with the fabric types and interfacing options, let's explore some techniques for sewing ultralight fabrics:

1. Pair Ballpoint Needle with Polyester Thread: Use a ballpoint needle, which has a rounded tip that slides between the fabric fibers instead of piercing them, reducing the risk of snags or runs. Pair it with Tex 30 polyester thread, such as Gutermann Mara 100, which is strong and lightweight, suitable for ultralight fabrics.
2. Avoid Zigzag Stitches: Zigzag stitches can cause the fabric to stretch and distort, especially on lightweight and slippery fabrics. Instead, opt for straight stitches for all construction seams resulting in better stability and seam strength. Zigzag or overcast stitch patterns are appropriate for finishing raw edges within a seam allowance.
3. Adjust Stitch Length: When sewing construction seams on slippery fabrics, consider using a shorter stitch length, approximately 2.5 on the selector knob. A shorter stitch length helps to create tighter, more secure seams that are less likely to pucker or unravel, providing greater stability and durability to your garment.
4. Use a Straight Stitch Needle Plate: A straight stitch needle plate has a smaller needle hole, preventing the fabric from being pulled down into the machine and reducing the risk of jams or skipped stitches. To ensure compatibility with your sewing machine, it's advisable to check with the manufacturer for available accessories and needle plate options. This simple addition can make a significant difference in the quality and consistency of your stitching, particularly when working with delicate or lightweight fabrics.
5. Use a Walking Foot Attachment: A walking foot attachment helps feed both the top and bottom layers of fabric evenly, preventing shifting and puckering, especially on slippery fabrics. Walking foot attachment may not be suitable for super ultralight fabrics such as MEMBRANE 10 as the additional pulling may create drag lines.
6. Reduce Presser Foot Pressure: If your sewing machine allows, reduce the presser foot pressure to minimize the amount of pressure exerted on the fabric, helping to prevent stretching or distortion.
7. Use a Teflon or Roller Foot: If a walking foot attachment is causing drag lines or puckering the fabric, consider using a Teflon or roller foot attachment, which reduces friction between the presser foot and the fabric, allowing for smoother feeding and stitching on slippery fabrics.
8. Use Clips or Pins: Use sewing clips to hold the fabric layers together without leaving holes or marks. Use pins with seam allowances. Alternatively, use temporary fabric adhesive or glue stick to secure seams before stitching. Minimize pin holes when working with WPB and Sil/PU fabrics.
9. Properly Set Thread Tension: Adjust the thread tension according to the fabric and thread being used. Test on a scrap piece of fabric to ensure the tension is balanced and the stitches are even and secure.
10. Sew with Slow, Even Speed: Sew at a slow, consistent speed to maintain control over the fabric and stitches. Avoid pulling or pushing the fabric through the machine, as this can cause uneven stitching or fabric distortion.
11. Practice on Scrap Fabric: Before sewing your actual project, practice stitching on scrap pieces of the same fabric to get a feel for how it handles and to adjust settings as needed.
12. Use an Extension Table: If your sewing machine is compatible, utilizing an extension table can significantly improve the handling of slippery fabrics. An extension table provides a larger, flat surface area around the needle, allowing the fabric to glide smoothly and evenly as you sew. This extra support helps to prevent fabric distortion and ensures more precise stitching, especially when working with lightweight or delicate materials.