<![CDATA[Gambier extract derived from leaves of Uncaria Gambier Roxb contain catechin and tannin which belonged to polyphenolic compounds. Gambier extract when added with ferosulfat salt will form a complex compound that can give a green color to black and can be used as a dye in the stamp ink. This study aims was to see how far the effect of adding glycerin and concentration of the Gambier extract solution against some physical properties and levels of tannin stamp ink. The ink manufacturing was done through a washing process of gambier, filtering, cube black manufacture, dissolution and formulation. The making of the stamp ink was done by a non factorial completely randomized design with a variation of the concentration of glycerin Ao = Without the addition of glycerin, A1 = 15% = 20% A2, A3 and A4 = 25% = 30% and the concentration of the extract gambier B1 = 20%, B2 = 25% = 30% B3, B4 and B5 = 35% = 45%. Results of the research showed that the addition of glycerin could increase some physical properties, especially against the homogenity of the ink. The best treatment was obtained on the use of gambier extracts 35% (B3) with pH 3.27, total solids 41.33%, tannin content 2.5788%, visual observation of color strength was clear and flat, viscosity was medium, not expand and not sticky, and homogeneous.ABSTRAKGambir berasal dari ekstrak daun tanaman Uncaria Gambier Roxb, mengandung senyawa katechin dan tanin yang termasuk golongan senyawa polifenol. Ekstrak gambir jika ditambahkan dengan garam ferosulfat akan membentuk senyawa komplek yang dapat memberikan warna hijau sampai hitam dan dapat digunakan sebagai pewarna pada tinta stempel. Penelitian ini bertujuan untukmelihat sejauh mana pengaruh penambahan gliserin dan konsentrasi larutan ekstrak gambir terhadap beberapa sifat fisika dan kadar tanin tinta stempel. Pembuatan tinta dilakukan melalui proses pencucian gambir, penyaringan, pembuatan cube black, pelarutan dan formulasi. Pembuatan tinta stempel dilakukan dengan rancangan acak lengkap non faktorial dengan variasi konsentrasi gliserin (0%, 15%, 20%, 25%, dan 30%) dan konsentrasi ekstrak gambir (25%, 30%, 35%, 40%, dan 45%). Hasil penelitan menunjukkan bahwa penambahan gliserin dapat meningkatkan beberapa sifat fisika terutama terhadap homogenitas tinta. Perlakuan terbaik diperoleh pada penggunaan ekstrak gambir 35% dengan pH 3,27, padatan total 41,33%, kadar tanin 2,58%, pengamatan visual terhadap kekuatan pewarnan jelas dan rata, kekentalan sedang, tidak mengembang dan tidak lengket serta homogen.]]>
