Depends on the setup. Will they be running it as a spot colour? What's it for?
If not and it's CMYK I would set it up as rich black (30/40, 0, 0, 100). The black used would also depend on what else is on the job too. (eg: if there is a lot of cyan around the black areas I would be adding some magenta to the mix.)
@Looney I wouldn't be using a 199% black if it's anything other than a solid block.. would be very messy with anything reversed out of it.
THEUNDERDOG - 33/33/33/100 worked fine on the print job we did, the corner of a photo was that mix and we wanted it to fade into colour used on the rest of the packaging
you are right - as you say depends on the job
with adding magenta or cyan to black, to me it all depends on what the overall look is, if i have a job where red is a prominent colour i add magenta (though cyan is seen as the conventional way), 20% used to be the norm, but no more
In that case I would go with a rich black, so 100% K + some combo of CMY in there depending on the artwork.
If it's by itself or has reversed out text I would go with 40,0,0,100 and as @Looney suggests, if it's over a full colour image, I would beef it up to around 20,20,20,100 (assuming it's uncoated stock).
Yeah, ask the printer. Every printer is different and the press operators know their machines better than someone here saying a CMYK value.
The values Illustrator and Photoshop spit out when converting from a Pantone colour to CMYK are very loose approximations. If you've got the CMYK breakdown colour swatch book and a Pantone colour swatch book then you can compare the two to get a better value.
But I would ask the printer in this case what their True/Rich Black value is.