Description You may wish to begin by reading the text widget conceptual overview which gives an overview of all the objects and data types related to the text widget and how they work together. Tags should be in the GtkTextTagTable for a given GtkTextBuffer before using them with that buffer. gtk_text_buffer_create_tag() is the best way to create tags. See gtk-demo for numerous examples. The "invisible" property was not implemented for GTK+ 2.0. It is working (with minor issues) since 2.8.