Thoughts on vertical shiplap for jib doors vs. standard trim?

I stopped trying to use solid wood shiplap for these becasue the expansion always gave it away by mid-August. Now I lean towards using a high-quality MDF core with a thin veneer if I want that wood look. It stays much flatter. For the vertical lines, I usally space the grooves so the door seam lands exactly in one of the recesses. If you keep a consistent 3mm gap that matches your groove width, it stays fairly stealthy even when the air gets dry.

Regarding hardware, I moved away from Soss hinges years ago. They look clean but if your mortise is off by a hair, you are stuck. I started using Simonswerk Tectus concealed hinges instead. Being able to adjust the door in three dimensions after it’s hung makes the alignment process much less of a headache. It costs a bit more, but it saves hours of frustration.

I honestly think a tiny hint of a seam is better than a door that rubs or sticks. I usually aim for a clean shadow line. If the gap is uniform, the eye tends to pass right over it anyway.

I actually disagree about the MDF approach. While it’s stable, it lacks the character of real lumber that most clients are paying for when they ask for a custom "secret" door. I’ve found that instead of trying to hide the seam inside a shiplap groove, it’s better to use a heavy-duty Rixson pivot hinge and go with a flush-inset design. When you use a pivot, you can carry a lot more weight, which allows for a thicker, solid-core build that won't warp as easily as a thin veneer panel might.

Regarding the expansion, I ussually leave a slightly larger gap—about 1/8th of an inch—and paint the interior of the jamb and the door edge a matte black. This creates a shadow line that looks intentional rather than like a failed attempt at a seamless fit. For me, the giveaway isn't the seam itself, but when the door starts to sag becuase the hardware wasn't beefy enugh. Soss hinges are okay for light cabinets, but for a full-sized jib door, you really need that floor-mounted pivot to keep everything square over the years.

Forget the Rixson for a standard jib; I’ve been running the Sugatsune HES3D-E190s lately and they’re a game changer. If you're worried about the seams, the secret is the catch. I always pair my concealed hinges with a Precision PLS24 PRO magnetic catch. It pulls that door into a dead-flat plane every time, so you don't get that annoying 1/16" proud edge catching the light.

Also, if you’re dead set on real wood, back-prime everythign with two coats of Zinsser BIN. It seals the grain enought to kill most of that seasonal movement. Just make sure your reveal matches the kerf of your saw blade if you’re doing the shiplap yourself.

I'm just starting out with basic trim work, so all these hinge names like Tectus and Sugatsune are totally new to me. Are those types of hinges somthing a beginner can install with basic tools, or do you need a specialized router jig to get them to sit right? I’m also curious about the MDF veneer idea—is that something I can buy pre-made, or do you have to glue the veneer yourself to keep it from warping? I'd hate to spend a ton on hardware just to have the door look wonky becuase I didn't know how to handle the wood.

Back in the day we didn't have these fancy adjustable 3D hinges. We used standard butts and just got real good at shimming. If you're worried about the wood moving, try quartersawn white oak—it’s a lot more predictable than that flat-sawn stuff. Also, if you want it truly hidden, forget the shiplap and look into 'bookcase' doors. A bit of weight on a bottom-bearing pivot and some clever trim work will hide a seam better than any groove. Just make sure your header is beefy enough; I've seen too many of these sag and ruin a floor because the builder didn't think about the load.

Don't stress the router jigs for those 3D hinges. Most brands sell a plastic template that's dirt cheap and makes it foolproof. If you're realy worried about the seasonal movement, I've had luck using a touch of dark paint inside the gaps before hanging everthing. It creates a deep shadow line that hides any slight shifting when the humidity spikes. Also, if you go the pivot route, make sure your header's beefy enugh. Nothin' ruins a 'hidden' door faster than a sagging frame that starts dragging on the floor after six months.