<![CDATA[Paste indigo pigment having blue colour was produced from fermentation of indigofera tinctoria leaves and twigs. Having was very popular dye and was used especially in textile industries and leather industries of fur. The aim of the study was to the optimum concentration of indigo pigmen on dyeing of suede leather. The materials used in study were crust suede leather, indigo pigmen, wetting agent, soda ash, ammonia, formic acid sulfonated oil, and redactors such as palm sugar. The dying of leather using indigo pigmen was principally similar with common dyeing and pH of indigo is 11.5, however pH on several steps must adjusted. Variation of the concentration of in dyeing was 0.5, 1, and 1.5% respectively. Performance test were of conducted for dye penetration, colour rub fastness (dry, wet), sweat resistant, and sun light resistant for 6, 13, and 20 hours respectively. The results showed that the optimum concentration of pigmen indigo was 9% dyeing and 1 % for topping with level dye, indicated appropriate penetration dye into the cross-section leather, no fading was performed by dry colour fastness test (score 4/5) and wet colour fastness test (score 4), good sweat resistant (score 5), no colour fading on the exposure to sun light for 20 hours (score 4). Keywords: Indigofera tinctoria, pigment, indigo, “suede” leather. ABSTRAK Pasta pigmen indigo merupakan zat warna biru yang dihasilkan dari fermentasi daun dan ranting tanaman Indigofera tinctoria. Pemanfaatan pigmen indigo pernah popular terutama dalam industri tekstil dan pernah pula digunakan untuk pewarnaan kulit terutama pada kulit samak bulu (fur). Tujuan penelitian adalah untuk mendapatkan konsentrasi optimum pigmen indigo pada proses pewarnaan kulit suede (bludru). Bahan penelitian terdiri atas kulit kras bludru dari kulit kambing, pigmen indigo, bahan pembasah, soda abu, amoniak, asam formiat, minyak sulfonasi dan reduktor (gula merah). Pewarnaan kulit menggunakan pigmen indigo pada prinsipnya sama dengan proses perwarnaan kulit pada umumnya, tetapi karena pigmen indigo bersifat basa (pH = 11,5), maka pH pada beberapa tahapan proses perlu diatur. Variasi konsentrasi pigmen indigo pada pewarnaan kulit berturut-turut 3,6, dan 9% dan konsentrasi pigmen indigo pada topping berturut-turut 0,5; 1,0; dan 1,5%. Uji mutu kulit hasil pewarnaan meliputi uji kerataan warna, tembus cat, ketahanan gosok cat (kering dan basah), ketahanan keringat, dan ketahanan terhadap sinar mathari selama berturut-turut 6, 13, dan 20 jam. Hasil penelitian menunjukkan bahw akonsentrasi optimum dicapai pada penggunaan 9% pigmen indigo pada dyeing dan 1% pada topping dengan hasil pewarnaan rata, warna cukup tembus kedalam penampang kulit, tidak luntur terhadap ketahanan gosok cat secara kering (nilai 4/5) dan secara basah (nilai 4), ketahanan terhadap keringat sangat baik (nilai 5), dan warna tidak pudar oleh sinar matahari selama 20 jam (nilai 4). Kata kunci: Indigofera tinctoria, pigmen indigo, kulit kras bludru.]]>
