I'm trying to prep my floor for acid staining. I used to have linoleum flooring down (12" x 12" squares). I have pulled that up and removed the glue but the design of the linoleum is still on the cement. Probably cause it was on for over 10 years.
I was going to sand the floor to get rid of the design but I have read that if you sand the floor before acid stain that the stain wont work.
My experiences with the ghosting of a tile grid is that they dont go away. We did an office building where the polishing/profiling contractor i hired ground into the aggregate + it was still there... up to an 1/8" into surface. Overlaying the concrete is your best bet to get rid of it. We had to do some master trickery to even cover the grid with waterbased stains + had little show.