Tonus is a variety of flax-fiber (Linum usitatissimum L. f. elongata), primarily intended for the production of flax fiber. The plant is mid-season with a vegetative period of about 85 days, reaches a height of about 82 cm, and is characterized by average resistance to lodging and shattering. The seeds are dark brown, and the capsule is large, which contributes to high yield: about 5.8 centners of seeds and 40.6 centners of flax straw per hectare. The fiber content in the plant is 30.4%, and the yield of long fiber reaches 27%, making this variety in demand for intensive cultivation technologies with the use of nitrogen fertilizers. Flax obtained from the Tonus variety has high consumer qualities. Natural fabric made from flax fiber is distinguished by its strength, durability, and hygroscopicity, capable of absorbing up to 12% moisture, which provides a cooling effect during wear. Flax fibers are resistant to acid effects, which makes the fabric softer after acid treatment, however alkaline solutions reduce its strength. The fabric withstands high temperatures up to 170 °C and has good lightfastness, surpassing cotton in this indicator. A wide range of products are made from Tonus flax: bed linen, clothing – shirts, dresses, suits, skirts, trousers, t-shirts, as well as headgear. The fabric is hypoallergenic, breathable, and practical to use. For care of flax products, washing at temperatures up to 90 °C is recommended for natural fabrics and up to 60 °C for dyed ones, careful use of bleaches, and drying in an unfolded state to prevent wrinkling. Iron flax items at high temperature with a steam function, and store them in cloth or paper bags to avoid absorbing foreign odors.
