Extract from Bonnie Dalzell:
"Dominant black is a black in which, in the absence of white markings and greying, the dog is black to the toes and does not show the sharp bicolor marks on the cheek seen in black and tans. It is called dominant black because a dog bred to an ay red (as the the sabled reds below) will produce black dogs without tan. In fact black dogs will appear no matter what the color of the mate. Since the dominant black can mask (ie carry) ay red or black and tan (at), a dominant black dog can produce colors other than dominant black, but a heterozygous dominant black will still produce roughly 50% dominant black pups. A black and tan dog bred to an ay red will only produce black and tan dogs if the red dog also carries the black and tan allele. A confusing occurance is that some of the dominant black dogs can produce 'chinchilla' colored pups [see next set of pictures] but the 'chinchilla' dogs, if bred to reds or black and tans can produce dominant blacks."