Discharge printing - Bassen

A method in which a paste liquid containing a discharging agent (discharge paste) is printed on plain-dyed fabric and then steam-heated to create a discharge pattern in that area. There are three types of printing method: white discharge, colored discharge, and semi-discharge. In white discharge, the ground dye is completely decomposed and decolorized, in semi-discharge this is not done completely, creating a pattern in a color lighter than the ground color, and in colored discharge, a dye that is resistant to the discharging agent used is mixed into the discharging paste, and the dye is allowed to adhere to the area at the same time as it is discharged. Oxidizing agents are also used as discharging agents, but reducing agents such as Rongalit C, Dechlorin, and stannous chloride, which are less likely to cause fiber embrittlement, are often used. Discharging agents are mainly selected based on the properties of the fiber and ground dye. However, there are few vat dyes or disperse dyes for polyester that are capable of discharging.

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

無地染めした布に抜色剤を含むのり液(抜染のり)を印捺，蒸熱処理して，その部分に抜き模様を表す方法．なせん法の一つで，白色抜染，着色抜染，半抜染の3種類がある．白色抜染は地染めの染料を完全に分解，脱色するもの，半抜染はこれを不完全に行って，地色よりも淡い色で模様を表すもの，また着色抜染は用いる抜色剤に耐える染料を抜染のり中にまぜ，抜色と同時にその部分に染着させる方式である．抜色剤には酸化剤も用いられるが，繊維脆化を起こしにくいロンガリットC，デクロリン，塩化第一スズなど還元剤系のものが多用されている．抜染剤はおもに繊維と地染め染料の性質によって選択される．しかし，建染め染料やポリエステル用分散染料には抜染可能なものが少ない．

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