How to achieve contrast in a black-on-black design
I'm trying to achieve a black-on-black design on a business card. See link here: AHC 180 Youth Ministry Business Card. The large black arrow and the grunge splotches are a rich black of 40-40-40-100, and the card background is 0-0-0-95. The card is being printed offset and UV coated, probably via an online printer (I'm ordering them through a third party and don't have access to the printer.) It's important that there be enough contrast between the blacks so that the rich black portions are distinguishable, but I still want the background to have a black/almost black appearance. Would I be better to use some version of a rich gray for the background rather than a 95% (or lower) black? I'm open to all suggestions.
Don't use a black only at 95%.... make 2 different rich black.
One could be 40-40-40-100 and the other 30-30-30-90.
Personally I recommend you use a bit more Cyan in your recipes rather than making all your CMY values equal: if the printer is not well calibrated (or is digital), a black with more cyan will still look steel black and not dark brown (eg. 40-30-30-100 and 35-25-25-90). You don't need to use a 10% difference, 5% more of cyan is enough.
Usually, if you have a 10-15% difference in your black, it will give a nice soft contrast and will not really look gray. 5% is risky and might not be clearly visible; it could work well though if you were using a spot varnish.
With the 2 rich black recipes I suggested you it should look similar to your example.
Also, when you add a lamination or varnish, it can make the colors little bit darker. Not much, but enough to lose some contrast if you use a 5% difference only between your 2 blacks!