Metallic after cmyk usually, BUT if you're using the MetalFX inks (and paying a buttload of cash for the license) you need to print metallics first - you can get some great effects with this system but it is not cheap. Inks start at 11gbp/k up to 200gbp/k!!

We've recently installed a 6 colour Komori and used an evaluation kit to print our inhouse brochure printing silver, gold then cmyk over the top - I have to say it looks really cool!

Open up the links palette - go to the grey area at the bottom of the palette, click in it and then hit the update icon.