How can I print onto black paper?

White ink exists in water based, (Eco)solvent, UV curable and Latex ink sets for inkjet printers. Do a search and I believe even Epson has a printer with a white ink option .... a Google, yes:

http://www.epson.com/cgi-bin/Store/jsp/Pro/SeriesStylusProWT7900/Overview.do

Opacity is not obtained by a white mineral pigment but more or less by optical refraction, reflection, diffraction etc so quite complex, comparable to what happens in dispersions, milk for example. It does not deliver the opacity of a TiO2 filled paint and the thin ink layer achieved with inkjet printers is not helping either. Like in conventional printing it helps to lay down a metal ink layer first (exists too in inkjet ink) and white on top followed by color inks if needed. Opaque color inks that deliver a wide gamut do not exist either so you better lay them on top of an opaque white to get opacity and color gamut. Even in silkscreen printing only the spot colors can be more or less opaque, if full color prints have to be made there is transparency needed for color mixing to get a wide gamut, ink layers in silkscreen are much thicker though.

Some of the Durst UV curable inks deliver a nice white print on black: 2 layers more opaque. One layer with a nice translucency on transparent or metal media, the other media that can use white ink.

Some printers rely on white light reflection from the media to find sheet edges when the paper is loaded. It will not work with black paper. Other printers use infrared sensors and/or mechanical switches to achieve the same and will accept black media.

In most cases it is easier to start with white paper and print color + opaque black and keep white bare to get what you need.

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Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
December 2012, 500+ inkjet media white spectral plots.