Conventional wisdom says if a lap doesn’t have channels it won't flow and polish the mirror but there is a growing trend toward NO channels! In other words a solid lap. I used a channeled lap in the beginning of polishing but then I started having problems with contact after I re-channeled (I ran into a vicious cycle, the channeling deformed the lap enough that it had to be repressed which meant new channels which meant re-channeling, and so on…) , so I re-pressed and finished the mirror using only a razor for micro faceting and a solid lap. I found that contact was better and maintaining the lap was much easier, although I used a relatively soft lap and a harder lap may not have worked as well. The photo shows a channeled lap –I couldn’t find a picture of a solid lap
