Technical
Silnylon / Silpoly
shelterultralightshellpack

Needle

PrimarySchmetz Microtex Sharp 70/10
AlternativeSchmetz Universal 75/11

Thread

  • Gütermann Mara 120 (fine thread to minimize hole size)

Machine Settings

Singer Heavy Duty 4452
Stitch length1.8–2.2 mm
Stitch width0 (straight stitch)
Tension3–3.5
Presser footTeflon foot essential

Quick Tips

  • Silicone coating makes this extremely slippery. Tissue paper above and below is highly recommended
  • Every seam needs seam sealer for waterproof performance
  • Work in a warm room. The silicone coating stiffens in cold
  • Bias edges stretch dramatically. Stabilize before sewing

Detail

Silnylon and silpoly are silicone-impregnated ultralight fabrics for tarps, bivy covers, wind shells, and stuff sacks. The silicone gives them water resistance and low friction. It also makes them brutal to sew. They slide, bunch, and shift constantly. Tissue paper is the most reliable fix: sandwich the fabric, sew through, tear the paper away after. Keep seam allowances narrow and consistent (8–10mm) for light builds. Seal every finished seam (silicone-based for silnylon, urethane for silpoly). Not a beginner fabric. Rewarding for ultralight shelter and bivy projects.