Painter wants a satin finish on a big living room wall that gets raking light from a bank of windows.

For a satin finish in raking light, you need a Level 4 drywall finish.

What Level 4 means:

• All seams taped and mudded
• All fasteners concealed
• Three coats of joint compound total (tape coat + two finish coats)
• No sanding swirl marks - this is critical under raking light
• Surface is smooth but not perfectly flat like Level 5

Why not Level 5? Level 5 (skim coat over everything) is overkill for satin paint. It's expensive, time-consuming, and satin paint will hide minor imperfections that Level 4 leaves.

Key execution tips:

• Use a 12-inch knife for final coats to minimize ridges
• Sand with 120-grit then 150-grit screen - don't skip this
• Prime with drywall primer (not general primer) - this seals the compound evenly
• Two coats of satin paint minimum

Red flags to watch:

• Any visible screw heads or tape edges = need another skim coat
• Sanding scratches = re-prime or they'll telegraph through paint
• Uneven compound absorption = patchy paint

The raking light will expose every flaw, so take your time on the final coat and sanding. A rushed Level 4 job will look terrible in that lighting. If the painter complains about the prep work, tell him it's the difference between a $500 paint job and a $2000 one.

Level 5 finish is mandatory. Raking light + satin paint = every ripple, ridge, and joint photograph will show. Level 4 is insufficient.

What Level 5 actually means (GA-214 / ASTM C840):

1. Tape coat: Embed paper tape in setting-type compound (e.g., 45-min).
2. Fill coat: Second coat over joints/fasteners, feathered wide.
3. Finish coat: Third coat, wide feather, sanded smooth.
4. Skim coat: *A full, thin skim coat of all-purpose or topping compound over the entire wall surface.* This equalizes suction and texture between paper facing and joint compound.
5. Sand: Light pole-sand (150–220 grit) to remove tool marks only—don’t sand through the skim.
6. Prime: PVA drywall primer or high-build surfacer primer (e.g., Zinsser Surfacer, Benjamin Moore Fresh Start High-Build) to further mask micro-imperfections.

Coats on the board: Minimum 4 compound passes (tape, fill, finish, skim) + primer. Coats on the painter’s side: Primer + 2 coats satin.

Pro tip: Run a 12–14" knife or magic trowel for the skim. Keep it wet, work fast, don’t overwork. If the wall is >10' tall, consider a hopper-applied skim (spray texture set to "smooth") followed by a knockdown pass with a wide knife—faster and more consistent on big fields.

Code ref: IRC R702.3.1 / GA-214-2010 Level 5.