I had a prof painter come to my house to paint a light green over an already light green on the walls of my nursery but my husband had outlined his beautiful murals on the previous walls in black permanent marker and the painter did not prime first - he just kept putting coats of paint (total of 4) and I can still see the outlines bleeding thru! what do we do? what are our options?
If he's using emulsion (water based) paint, it will never cover it. You need an oil based sealer. You can use regular undercoat to seal marks like that.
Otherwise get som Stain Sealer or Stain Blocker sold at most of the big sheds / screwfix etc