Hi all, Getting ready to paint my ceiling and walls. Ceiling, fire breast and an archway have all been freshly plastered and now dry. The other walls were in pretty good condition minus hairline cracks. In attempt to avoid filling and sanding every hairline, what is my best plan of attack here since i'm intending on painting straight on the walls? I've been told to mix some PVA into the first coat of paint on the walls but that seems a bit odd, i've also seen a few primer products that claim to cover hairline cracks but really mixed reviews on these Thanks in advance!