I'm awakened the costs involved, as well as the method, which is why I didn't ask about them. Thanks though!

From what I understand it is a modification of the hooded gene, however, as per standards dalmatian rats are not to be hooded. I'm not knowledgeable enough on genetics to figure out how to get hooded rats to express dalmatian in litters, nor do I have the space to take on such an undertaking, so hence just looking for the variety itself.