Pango is really useful for creating markup strings although it does some caveats. It is markup for display purposes and not interactive editing. Some work has been done in bridging the gap between the display widgets and the text editor by creating preset markup tags which are meaningful names as tag whilst being valid pango strings. Pango also has some convenience tags although extending this list is not possible at all, nor its is directly possible through the Gtk api to directly convert pango attributes to tag properties or vice versa. To exchange formatted data between the text edit and display widgets needs a degree of creative programming on the part of the coder: set txt [gnocl::text -useMarkup 0 -wrapMode word] gnocl::window -child $txt -setSize 0.2 -onDelete {exit} $txt tag create "<span rise='3000' font_size='small'>" -fontRise 3 -fontSize 8 -foreground red -editable 0 puts [$txt tag names] $txt insert end AAAA -tags [$txt tag names] $txt in