Stretch & Fleece
Polartec Alpha
insulationmidlayerultralight

Needle

PrimarySchmetz Stretch 75/11
AlternativeSchmetz Universal 80/12

Thread

  • Gütermann Mara 100 polyester

Machine Settings

Singer Heavy Duty 4452
Stitch length2.5–3.0 mm
Stitch width3.0–4.0 mm zigzag
Tension3.5
Presser footWalking foot strongly recommended

Quick Tips

  • Alpha is fragile until sewn. Handle cut pieces minimally to avoid distorting the batting structure
  • Use a longer stitch length than you'd expect. Short stitches perforate the material
  • Baste layers together before final sewing to keep everything aligned
  • Face fabric and lining do most of the structural work. Alpha is the fill layer

Detail

Polartec Alpha is active insulation: lofted batting for high-output use. Unlike down, it insulates when damp and breathes well. In MYOG it sandwiches between a face fabric and lining that carry the seam stress. Alpha is fragile at the edges and pulls apart if handled roughly before it's enclosed. Keep allowances wide (12–15mm) and sew slowly. Channel-quilt the Alpha to the face fabric to stop it shifting. Intermediate project, big payoff in vests and active jackets.