Pure indigo and natural dyes

• The use of exclusive Japanese fabrics makes the Strategic Business Unit denim collection distinctive.
• Textile manufacturing is one of the oldest human activities. In order to make textiles a fibre from which spinning can make a yarn is required. Knitting or weaving to make a cloth processes the yarn. The machine used for weaving is the loom. Weaving is the textile art in which two distinct sets of yarns or threads, called the ‘warp’ and the ‘weft’, are interlaced with each other to form a fabric cloth. Cloth is ‘finished’ by what is described wet process to become fabric.
• Finishing refers to any process performed on yarn or fabric after weaving to improve the look, performance, or ‘hand’ (feel) of the finished textile. SBU denim fabrics are obtained by using finishing and dyeing techniques, which have been used with hand weaving for centuries in Japan.
• Dyeing is the process of imparting colours to a textile material by treatment with a dye.
• For most of the thousands of years in which dyeing has been used by humans to decorate fabrics, the primary source of dye has been nature, with the dyes being extracted from plants. SBU Japanese cotton and denim is dyed with a range of ancient natural dyes.
• BLUE is the colour of the INDIGOFERA TINTCTORIA a plant from which the indigo colour is obtained. Because the indigo pigment is not water soluble it cannot be dyed through boiling as other plant dyeing, in fact it has to be fermented to become soluble.
• Yarns are soaked into indigo liquid then, being oxidized by oxygen in the air after picking them out from the vat, the indigo pigment return to the original indigo blue. Indigo threads used for Strategic Business Unit denim fabrics are soaked and dried fifteen to twenty times. Indigo strengthens the materials and the quality of the colour’s richness increased with the time.
• Indigo was also believed to have medical properties and leaves were used in Japan to treat insect and snake bites as well as fever and stomach disorders. In Japan, indigo became especially important in the EDO period when it was forbidden to use silk.
• Even today indigo is very much appreciated as a colour for the summer kimono YUKATA, as this traditional clothing recalls Nature and the blue sea.
• Many Japanese manufacturers apply sulphur dye before the customary indigo dye: this is used to create a grey or yellow ‘vintage’ cast.
• SBU black jeans are dyed with indelible natural inks, a time-honoured Japanese method of fabric production. SUMI ink, literally ash or soot, is a carbon based permanent black ink. Water is placed into the well of the ‘suzuri’ stone and the carbon ink stick is rubbed against the stone. Water is added to create various shades of black ink. BLUE / BLACK special edition jeans included in this selection is obtained by mixing black ink and indigo dyed fabrics.
• SBU special edition jeans are realized using a ‘mud’ dyed fabric from an island located in Kyusyu prefecture.
• The cloth is dyed many tens of times with the juice of a member of the rose family obtained by boiling the trunk and roots in a pot for 14 hours. The tannin in this juice turns the thread a rust colour. Then the dyed threads are impregnated with mud. The iron in the mud causes a chemical reaction with the tannic acid making the tread soft at the same time as producing the characteristic brown colour.
• RAW denim has a distinct section in Strategic Business Unit jeans collection. Raw denim, as opposed to washed denim, is a denim fabric that is not washed after being dyed during its production.
• Much of the appeal of raw denim lies in the fact that with time the fabric will fade in a natural way. The body of the person who wears the jeans and the activities of his daily life affect such fading. This is what many enthusiasts reputed to be the better and only way to obtain authentic and unique ‘distressed’ jeans. To facilitate the natural distressing process, some purist of denim will often abstain from washing their jeans for several months, though it is not strictly necessary for fading.
• SBU denim garments are pre-washed after being crafted in order to eliminate any shrinkage, which could cause an item to not fit after the first wash.
• Strategic Business Unit denim collection is entirely made in Italy.