Every inkjet vendor tells you that you should only use their ink cartridges with your printer.  If you are prepared to take responsibility for the consequences, however, there are a lot of different types of ink available for you to use.  Note that some ink and paper combinations work much better than others.

Colour Inks

One reason for using alternative colour inks in your printer is economy; another might be to make your prints last longer by using so-called archival materials.  You can buy alternative inks in cartridge form, or buy in bulk to reduce costs.  If you buy bulk inks, you can either refill cartridges yourself or invest in an inking system for your printer.

Colour inks can be made from dyes (like most OEM inks), from pigments (which are generally longer-lasting) or be a hybrid of the two.

• Generations by MediaStreet.Com
• Fotonic Photo Inks by Lyson
• Lysonic Archival Inks by Lyson
• MIS Archival Ink by MIS Associates
• MIS Epson compatible dye-based ink by MIS Associates
• Staedtler [site] inks for large format printers (Epson 3000 and up, HP DesignJet, etc.) [site]
• Van Son inks
• Xtreme gamut inks

Monochrome Inks

Most colour ink sets do rather a poor job of monochrome work, at least by the standards a monochrome photographer would set.  Using colour inks tends to produce a print in which the colour is not quite neutral over the full tonal range from black to white, and there is a tendency for this colour cast to shift with time.  You can get round these problems by printing with only black ink (which gives a very grainy result on most printers) or by using cartridges containing several different colours of grey instead of colours.

This process is most often used on the four-ink printers rather than the six-ink "photographic" ones, and is commonly referred to as quadtone printing.

• DigitalPlatinum by ConeTech
• Lyson Quad Black Cool Tone Inks by Lyson
• Lyson Quad Black Neutral Tone Inks by Lyson
• Lyson Quad Black Warm Tone Inks by Lyson
• MIS Quads by MIS Associates
• Piezography [site] by ConeTech for the Epson 3000 and 1160 printers

Small Gamut Colour Inks

What if you want to do mainly monochrome work, but want to vary the image colour slightly?  If you had all the time in the world, you could mix your own inks; another alternative is an ink set which is, well, not very colourful.

• American Ink Jet [site] (mostly a rumour, not backed up by their web site)