Digital Watermarking of printed images is an important capability for many applications. Visually detecting the watermark through, e.g. UV illumination, enables the watermark use in uncontrolled environments. In our previous work, UV watermarking was proposed for in dispersed dot scenarios (assuming the use of standard colorants). This talk describes the generalization of that concept to clustered dot scenarios thereby allowing the creation on standard printing equipment, such as offset or xerographic printing.