I don't know what a PK canvas is. The canvas I have is Epson Exhibition Canvas Natural Satin and the ink lifts with either the BK or MBK, but really all the colors (Canon Lucia) come up.
But, OK, now we are getting to at least one of the issues: I'm using a bad combination of canvas and ink. At least mearussi has a way of dealing with it. Thank you. I could use that approach, or perhaps there is another canvas that I should use. What about Canon canvas?
Now, back to the OP, will varnishing the canvas properly avoid ripples?