Four spools of Seraflex in the colors you'll actually reach for first — black, white, a soft grey, and a true red. Seraflex is Mettler's elastic sewing thread, and it solves a problem every knit sewer runs into: a straight seam that pops the first time the garment stretches. The thread itself gives, up to about 65% elongation, so the seam moves with the fabric instead of fighting it. Leggings, t-shirts, swimwear, sportswear, cuffs and waistbands, lingerie — anywhere a conventional polyester would snap.

Ash Mist #0331, White 1 #2000, Country Red #0504, Black #4000

Specs: 4 spools × 142 yd (130 m) · No. 120 · 100% PTT continuous filament · Nm 83/3 · needle Nm 70–80 · Mettler item SFX4-KIT (Art. 7840)