Is the old-school Craftsman butt joint method still the cleanest way for window casing?

The trick with those wide pine butt joints is all in the prep work before you even pick up a nailer. Pine is notorious for shrinking and expanding, wich is why those joints often open up after a single season. If you want them to stay tight without a gallon of wood filler, try **glueing and pocket screwing** the entire casing assembly togather on a flat table before you even bring it to the window. It creates a solid frame that moves as one unit. If you're just nailing them into the studs one by one, the wood movement is going to win every time.

On the design side, this style is the standard for hiding rough window installs where the jambs aren't perfectly flush with the drywall. A mitered corner in that scenario is a nightmare. But you have to be careful with those radiused edges on stock lumber. If you're using 1x4 or 1x6 from a lumber yard, they often have a slight round-over on the long edges. If you just butt those together, you get a "V" groove that looks sloppy and unfinished. I always rip about an eighth of an inch off the mating edges to get a dead-flat, square surface that basically disappears when joined. Homeowners definitely still love the deep sills. I call them plant benches. As long as the stool is thick enough to look structural and not like a flimsy piece of trim, it’s a great feature. That thin molding near the ceiling you're seeing is likely a picture rail or a small cove. It can definitely mess with the visual weight if your window headers are too chunky. If you have a 6-inch header and only 4 inches of wall space before the ceiling trim starts, the room starts feeling top-heavy and cramped. Sometimes you have to scale back the header height to let the room breathe.

As for the sanding, pine is unforgiving. It hides saw marks untill you hit it with a finish. I ussually sand up to 180 grit and use a **pre-stain conditioner** even if it's just a light tint. And don't forget to break the sharp edges just a tiny bit with a sanding block after you've joined everything. It makes the whole thing feel more custom and less like a bunch of construction lumber slapped around a window frame.

I never thought about ripping the edges to get rid of that factory round-over. I’ve definately seen those 'V' grooves on my test pieces and just thought I was cutting them wrong! Does that make the boards look significantly narrower if you're doing it on both sides? Also, for the pocket screws, do you have to use special coarse screws for pine so they don't just pull right thru? I'm terrified of splitting the wood right at the end of the board where it's most visible.

Coarse threads are a must for pine, but I’ve had better luck using biscuits for those butt joints. It keeps the faces flush without having to plug holes later.

Also, don't forget the apron under that deep sill. If you use a thin strip there, the window ends up looking top-heavy. I usally match the apron width to the side casings to ground the whole look. It makes that stool feel structural rather than just stuck on. Are you painting these? Pine knots are notorious for bleeding thru finish if you don't seal them with shellac first.

I always make sure the "horns" on the stool extend at least an inch or so past the casing. If they're too short, the whole window looks a bit stubby and loses that structural feel.

Since you're worried about the joints, try sealing the end grain of the header board with some wood glue mixed with a little water if you're staining. It stops the pine from soaking up way too much pigment and making the butt joint look like a dark, muddy line compared to the rest of the frame. It's a lifesaver for making those simple joints look intentional instead of just slapped togather.