Blue Print for Pharmacy

This is not really a blog. This is a curiosity I have been carrying with me ever since I have started living in Kolkata. I may sound stupid, but I really couldn’t find the answer to my this query and I am here to see if anyone could help me. Now my question to you is, could you please tell me, why many pharmacies are called Blue Prints? For example, a pharmacy named Good Health should have the name as Good Health Pharmacy or Good Health Chemist or Drugstore. Why do they name it as Good Health Blue Print? I have tried googling for the answer but couldn’t really find a solid reply to my question. If anyone knows the answer, please tell me. This itch is killing me.