When I was a teenager, I went on a bunch of mission trips with my church. Painting was something easy to hand off to an unskilled teenager, so I ended up doing a lot of that.
And back then, there was a process. Sanding, priming, painting, in that order.
I didn’t really understand why I had to do the first two steps, but I was in charge of absolutely nothing, so I did what I was told.
20 years ago, paint formulas were less advanced. Sanding and priming were necessary to help the paint adhere to the wall.
Today, however, paint formulas are more advanced.
In a typical wall application, priming before painting is unnecessary. However, if the surface is porous (like wood or fresh drywall,) a drastic color change is occurring, stains need to be covered, or the surface is glossy, priming before painting is necessary.
But the primer you’ll use for each reason is different, so keep reading!
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1. Porous Surfaces
You’ll need to prime before painting if the surface you’re painting in absorbent or porous. This includes materials like new drywall, wood, paper, cardboard and fabric.
Without primer, paint soaks into the porous surface, weakening it and requiring more coats to get the desired color.
Primer is cheaper than paint, so by priming first, you’re actually saving money (and time!) from the additional coats of paint you’d need to do to get the same effect.
The primer you’ll use depends on which surface you’re trying to paint. If it’s fresh drywall, I recommend 123 Zinsser Water-Based Primer.
This is Zinsser’s base-line (aka cheapest) primer, but it’s still an excellent product. It’s water-based, so it’s easy to clean up and doesn’t smell bad.
For new drywall, you really just need to seal it and move on, so this primer is the way to go.
For other, trickier surfaces like wood, I love Zinsser’s Oil-Based Cover-Stain Primer. Because it’s oil-based, it requires mineral spirits to clean up, plus it smells pretty bad, so it’s a bit trickier to use than the water-based primer.
BUT, it has a higher level of performance on tricky surfaces than the water-based primer, so the trade-off is worth it.
Plus, it covers up any tannin bleed-through from the wood, which is something that happens with certain woods.
I foolishly didn’t think to prime under the white spots of this little fox I made:
Do you see all the yellow? That’s the wood tannins bleeding through. I ended up throwing on a coat of oil-based primer and repainting.
I try to use disposable foam brushes so the clean up hassle is less of an issue, but even with that it’s my favorite primer.
Important: You may of heard not to paint latex paint on top of oil paint. This is true, it will not stick! But if you were worried, oil-based primer is different than oil-based paint. You can and should paint latex paint on top of oil-based primer.
Paper and Other Ultra-Porous Surfaces
Finally, if you’re working with a surface that is really porous, like paper, Zinsser’s B-I-N Shellac Primer is what you’ll want. It’s really expensive, plus it smells, and it requires denatured alcohol to clean up, so it’s a giant pain all around.
I’ve only used it once, and that was to deal with this drywall paper mess.
Relevant Note: This post isn’t sponsored by Zinsser. They’re just the primer I always use and keep on-hand, so it’s what I recommend. I’m sure there are other comparable primers to the ones I listed, but I haven’t used them, so I can’t rave about them like I can Zinsser.
2. Drastic Color Changes
My friend Lillie (of the goat milking stand) once bought a house that had a giant baseball painted on one of the walls. She tried painting over it, only to have the baseball shine through the new paint.
It was the baseball ghost of the nursery.
Primer was the answer to this problem (although in Lillie’s case, I don’t think she ever found the time to go back over and repaint. Children will do that to you.)
Primer is also great for dramatic color changes, like if you’re trying to go from a bright red to white.
Basically, if you’re worried your old color is going to peak through and alter your current paint color, you should prime first.
Zinsser’s Oil-Based Primer is what I’d pick for this. It’s great at blocking color, hence why it’s advertised as “cover-stain” primer.
The water-based primer isn’t really strong enough for this job, and while the Shellac primer would do as well, it’s a lot more expensive and probably unnecessary.
Similar to drastic color changes, if your wall is stained in anyway, you’re going to want a primer, especially if that stain is because of damage to the drywall.
If your stain is simple, like your kid colored on the wall or something, Zinsser’s Oil-Based primer is great.
But if you’ve got something more complicated, like smoke or water, where the wall itself has taken damage, you’re going to want Zinsser’s B-I-N Shellac Primer.
The shellac primer is specifically formulated to seal water and smoke damage and stop it from seeping through the paint.
4. Smooth Surfaces
I’m trying to think of a reason that a wall would be smooth, and failing. Drywall isn’t smooth. Plaster isn’t smooth. Wood isn’t smooth. Maybe whiteboard paint on a wall?
Either way, paint needs texture to grip to. If your wall is made of something like glass, plastic, metal or laminate, you’re going to need to prime it before painting.
(Side Note: I can’t think of a reason walls would be any of those things, but furniture is made of those things a lot. I prime furniture because it’s too smooth all the time.)
Zinsser’s Oil-Based Primer is a bonding primer, and it’s great for this. It’s what I use on all of my furniture project.
Am I starting to sound like a broken record yet?
5. Strong Smells
Have you ever moved into a home previously owned by heavy smokers? In addition to being stained (see above,) the walls smell like smoke.
Primer will seal in those smells. Zinsser’s Shellac Primer is still the way to go here, especially since you’ll need to deal with the smoke stains as well.
Smoke is my primary example here, because I think it’s probably the most common one, but primer will seal pet odors and cooking odors as well!