Aqueous dispersions of soot and other carbon materials, prepared in a manner similar to that used for preparing traditional Japanese ink, were developed as teaching materials for colloid chemistry. The protective colloid formed by the addition of glue is an interesting teaching material that allows visual understanding of various colloidal phenomena. In addition, such dispersions can be prepared using glue and various carbon materials (e.g., pencil lead, barbecue charcoal, C[subscript 60] fullerene, graphene, and carbon nanotubes), following an extremely simple and environmentally friendly method. The carbon materials are insoluble in water without the glue, highlighting the need for glue to act as a protective colloid in ink preparation. Herein, we describe convenient colloid chemistry experiments that are adaptable to a wide range of educational settings.