Not taping the spine. im learning on my whipped dog vintage. My first hone on the stone but i lapped with sandpaper i taped to a wood block. But on the 4k side it even acted like it was maybe uneven. Like the 2cm from the edge had this type of marking all the way down and even though the water placement followed my razor and stroke, i would get this type of "scuff" in certain spots only.

Edit: the only reason i ask is because referencing to lynn abrams video on his norton he just gets a nice slurry with no scuffing stuck to the stone so why is mine?