A: Several reasons to Prime before Paint
As Lisa suggested, covering up darker colors, going lighter is a very good reason. Others include changing paint sheen from say semi-gloss to flat or eggshell. Another one would be new drywall texture, sealing it up with flat primer, to allow the finish coat to lay down much more evenly. Many times before texture, a primer is used, allowing texture to adhere to the wall and ceiling surfaces, giving it something to grip to, other than sheetrock itself. Great response Lisa!
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