Flax-long fiber seeds (Linum usitatissimum var. elongatum) are certified planting material for fiber flax. Flax-long fiber is a technical crop for producing flax fiber: linen fabrics, ropes, twine, insulation, composite materials. Categories: original seeds (OS), elite (ES), reproduction 1 and 2 (RS1, RS2). Varieties: Alpha, Lira, Dashkovsky, Marilyn, Tverskoy. Germination not less than 80-85%, purity 98-99%+. Weight of 1000 seeds 3.5-5.5 g. Cultivation regions: Tver, Smolensk, Pskov, Vologda regions. Seeding rate 20-25 million viable seeds/ha. GOST 9668-75. Flax growing in Russia is concentrated in the Non-Black Earth zone: Tver, Smolensk, Pskov, Vologda, Kostroma regions - moderate humid climate is optimal. Russia is historically one of the largest producers of fiber flax. Agrotechnics: predecessors - cereals or row crops. Seeding rate 20-25 million viable seeds/ha. Seeding depth 1.5-3 cm. Harvesting in the phase of early yellow ripeness (maximum fiber quality). Flax pulling by flax combines, spreading in the field (dew retting 2-3 weeks), picking up the straw, primary processing at a flax mill. Flax fiber: long (combed, for fabrics) and short (tow, for ropes, insulation, composites). Weight of 1000 seeds 3.5-5.5 g. Export documentation: varietal quality certificate, phytosanitary certificate.