Bare, Unspoiled Sheetrock

• As long as your Sheetrock is free from stains and in good condition, you do not need to apply any sort of bonding primer. Paint will bond well to bare Sheetrock. Choose a specific type of latex paint based on your personal preferences. For an attractive, muted sheen, apply a satin or eggshell latex paint. For a glossy finish that's easier to clean, add a semigloss paint. Do not use a flat latex paint unless you're painting ceilings. This finish is difficult to clean and prone to staining.
  
  

Stains

• If your drywall is marred by ugly water, crayon, marker or smoke stains, latex paint will not permanently seal them. To prevent inevitable bleed-through, add a shellac-based stain-blocking primer specifically formulated to seal stubborn stains. You do not need to prime all of the Sheetrock --- just those areas where stains appear.
  
  

Grease and Oil

• Sometimes kitchen Sheetrock ends up marred by trace oily residues. If you add water-based latex paint to these areas, peeling will result. Although you can wash the Sheetrock with a degreasing soap, you're likely to miss some spots, and finish failure could follow. Instead, coat the Sheetrock with a light layer of oil-based primer. Be sure the primer is compatible with water-based latex paint. Read the labeling if you are unsure.
  
  

Considerations

• Although you do not need to add primer to previously painted Sheet Rock, you may have problems with adhesion, depending on the type of paint you're dealing with. Existing high-sheen semigloss paint will not bond well with fresh paint. Before adding a fresh finish, lightly sand the existing glossy paint until it feels rough. You do not need to sand existing satin or eggshell painted finishes.