A receiver medium for digital imaging comprises a substrate having a dye-receiving
surface bearing a coating comprising a highly branched functionalised polymer of
generally globular form, e.g. a dendrimer, dispersed in a host polymer. Functional
groups at or near the surface of the branched polymer, may interact with and bind
dye molecules having complementary functional groups, eg dyes as disclosed in WO
96/34766, e.g. by acid-base interaction, thus having the effect of chemically fixing
the dye within the coating on the receiver medium. Because dye molecules can be
chemically bound to the branched polymer in the receiver sheet, it is possible
to use host polymer materials of lower Tg than generally required in the prior
art, with the host polymer typically having a Tg of less that 50 C. This
means that dye molecules can have significantly increased diffusivity through the
coating, prior to interaction, resulting in a more even distribution of dye through
the coating than has been possible hitherto. The invention also covers a method
of making the receiver medium, a method of printing, and a receiver medium/dye combination.
