Ron, as Ole said: "This pre-emulsion coating has been used for a very long time, in fact I believe some of the earliest "gas light" papers were baryta coated!"

Virtually all commercial photo papers are sized or coated. If there is no coating or "sizing" the emulsion will indeed go down into the paper. That is ok if that is the effect you are looking for, but you may need to coat the paper yourself to achieve it.

You may want to look into Kodak's AZO printing process and materials. The AZO process is still alive and well (at least for the near term).