we have a lot of beautiful ceiling molding in our house and it took 3 winters with repainting in spring to finally not have seams open again. when we had white painted shaker cabinets installed last fall there was No Way i was going to say no to mdf. not a single seam on a panel opened up.

From a cabinet refinisher's point of view, once the paint begins to fail, the MDF will swell and begin to fall apart, making repairs very difficult and expensive. The extra you might pay for real wood construction will make any future repair/recoat issues simply maintenance matters rather than replacement nightmares

Does it make a difference that the finish is conversion varnish or factory finished rather than painted in site?

I believe that a factory finish is baked on and therefore holds up better. I am willing to be corrected, though.

That's what solid woodlooks like in winter when it shrinks.

That's also what painted doors look like at joins after a couple of seasons of expanding and contracting.

Give me factory painted MDF center panels any day. And MDO ply for the painted sides. Unless you like ugy splits showing through.

@Sophie Wheeler. What is MDO Ply?

Plywood with a very thin layer of moisture resistant mdf for the top layer. It provides a very smooth,stable, surface for paint.

Solid wood!

Sophie I just used that plywood for my closets that I had redesigned when I took out all the old wire stuff I put in when I bought the house.

Sorry built the house, wire was all I could afford them! I'm not sure I would want them for kitchen cabinets. That's just me.

An onsite finish of enamel or pigmented lacquer would be easier to repair, but more likely to fail, as they are both weaker than conversion varnish. A factory baked on finish is merely force cured in minutes rather than 30 days. But cured is cured and one not better than the other

I continually hear the advantages of conversion varnish over paint however when these factory cabinets are installed you have scratches from installation that are very difficult to retouch and unsightly flat nailholes to look at.

Just don't expect ''wood'' to behave like anything but wood. It expands and contracts, with resultant issues that WILL telegraph through the coatings. That is NORMAL. You can't have expectations of perfection that don't align with reality.

BTW, case goods haven't been built with ''solid wood'' since plywood was invented. Ply is no more solid wood than MDF is. In fact, if you wnt to get technical, because MDF is denser, it actually has more wood in it than does plywood. There are different grades of everything, including ply. Give me quality 45 lb furniture board any day over crappy stinking (literally!) Import ''ply'' that I've seen low end hacks use to site built fake ''kustom'' cabinets.

Sophie Wheeler it depends on what type of plywood is used. They do make plywood that does not off gas. You may pay more but I'm sure the cabinet maker would accomodate the client with that.
We bought some when building our own cabinet bases. Looks just as good stained up as the solid wood door frames.

I have maple with white paint and have never had an issue. Love my Brookhaven cabinets. Maybe I got lucky.

People need to understand that painting on wood is different than painting on metal or other stable materials. Solid wood by its very nature expands and contracts, a lot. A solid wood panel roughly 24" wide can expand and contract almost 1/4" in extreme cases and is not uncommon to expand 1/8" under normal conditions. MDF is a very stable product and not prone to the same characteristics of solid wood but should there be water issues is difficult to repair and in some cases needs to be replaced. Factory finishes are no better than others. Like Interior Cosmetics pointed out its really just a flash cure so that they can handle the doors quicker and move the cabinets out the door. The expectation that painted cabinets will not develop expansion and contraction cracks is somewhat unrealistic unless you never open your doors and/or have a humidity controlled environment. It's just the nature of the beast.

I expect to see and want to see expansion joints in kitchen cabinet doors just as I expect to see them in hard wood floors. If you can't accept a mitered joint or space between floor planks you should buy composites and laminates. This is also true in real stone vs quartz. I think it is a personal choice, and yes they do still make solid wood cupboard doors and frames.