The present invention provides pigmented inks comprising self-dispersing pigment
and an amino-containing compound. The addition of an amino-containing compound
to the self-dispersing pigment can improve the reliability and performance of the
ink in an inkjet printhead. The present invention also provides methods for making
a surface modified pigment comprising associating a self-dispersing pigment with
an amino-containing compound having no more than one primary amino group or one
secondary amino group.