Painting a room? Do you need to use primer on the walls if you are...

Do you need to use primer on the walls if you are fine art the same color? I do own some permanet marker grades on the walls from the kids and I need to repaint the room. I own tried to wash rotten the marker, but it doesn't come sour. The walls are an off-white, will the marker show through if I don't use primer?
Answers:    Get a can of spray Kiltz and cover the grades. I have have experiences with this. Some marker will bleed through several coats of wall paint unless you kiltz them first. Then you can prime the Kiltz spots with the wall paint and as soon as it drys, paint the entire nouns with the wall paint. You don't have need of to prime everything because the walls have previously be painted.

Professional Painter
Yes you should always prime your walls in the past you paint