CAT D - Kvadrat Tonus 4

Sculptural Stretch Wool with Intense Color Depth

Kvadrat Tonus 4 is an iconic, highly elastic wool upholstery fabric originally designed by Nina Koppel and updated for contemporary interiors by Kvadrat. Classified under BuzziSpace Category D, this ultra-premium textile is woven from 90% new wool and 10% Helanca (a specialized elasticizing yarn), offering exceptional stretch and recovery.

Tonus 4 is specifically engineered to hug dramatic curves, organic shapes, and complex sculptural seating without creasing or gathering. Its flat, dense surface weave showcases rich, saturated color intensity while maintaining acoustic transparency to allow sound waves to pass directly into underlying sound-absorbing foam cores.

Specifications

Composition: 90% virgin wool, 10% Helanca
Weight: 665 g/linen.m
Width: 140 cm | 55.11"
Abrasion resistance: 100,000 Martindale abrasion cycles, EN ISO 12947
Flammability: EN 1021-1/2 | BS 5852 part 1 | DIN 4102 B2 | Önorm B1/Q1 | NF D 60 013 | UNI 9175 1IM | US Cal. Bull. 117-2013 | NFPA 260 | IMO A.652 (16)
Light fastness: Grade 5-7, ISO 105-B02
Rub fastness: (ISO) dry 3-5, wet 3-5
Pilling: grade 3, EN ISO 12945
Care: Vacuum cleaning and dry cleaning.