I am not an expert on cabinets but I am a hobbyist wood worker. The problem with solid wood is that it expands and contracts with temps and humidity. That leaves gaps where you dont want them. Plywood or MDF with a veneer is much more stable than solid wood and will shrink and expand much less. As for the painting issue, some woods do not take paint very well. You can get resins bleeding through the paint. I would think that a factory applied paint job would fine but if he is custom making them and painting them in house he may not be set up to do a quality paint job - especially on bare birch. Good luck

Thanks, I had read that too but it's good to hear it from someone else. They are making the cabinets and the painter paints them. I am very sensitive to paint, glues, etc., so trying to cut down on the VOC's where I can. Just the OSB everywhere is killing me right now. Ordering zero VOC white paint, not sure how it will do. It's plenty expensive so should be good quality. I want white cabinets but if I have to have a lot of MDF anyway, I'm not sure if I should just do it all or not in my situation. Once it all out gasses awhile, I'm usually ok. The prefab vanities smell so bad I get instant headaches just opening the doors when looking at them in the stores.

Are they going to paint them with a spray gun? I think that's the only way to get a finish that doesnt have brush marks. Maybe design your cabinets to have as little detail as possible as those details will be tough to paint well and if you get movement in the wood that might reveal an unpainted surface. Good luck.

Just FYI...I have used a zero voc no formaldehyde plywood called Purebond on a project. Plywood will resist expansion and contraction much better than solid wood and for a shaker style cabinet (which is currently the most popular anyway) it will be better than mdf.

You can get birch veneered plywood (and lots of of species). I used maple veneered plywood for the closet organizers that I built.

Why deal with this cabinet maker? He just wants to do it his way - not very customer oriented - IMO. There are many good commercially available cabinets.

We have Omega cabinets - they are all plywood.

Omega Cabinets

Hardwood Venered Plywood

It sounds like they may be trying to educate you on the standard way they build cabinets, but it is possible to use all solid wood. Cost would most likely be affected though.

Every pre-finished cabinet line I have worked with, high end or low, has a disclaimer form they require to be signed by the cabinet dealer and the customer stating that you understand the properties of a painted finish. It has to be sent in with the order or else the order wont be processed. No matter how well it is painted, tiny "cracks" in the paint will show at the seams between the stiles & rails of a paneled cabinet door. schreibdave noted the reasons above - expansion & contraction from humidity changes will get to you sooner or later. It does not look horrible, they are tiny hairline cracks that you would have to be ok with. Go to a showroom and take a look at the displays. Up close you will see them & notice that you had most likely not ever noticed them before. BUT...once you know about something, it may bother you.

To answer your other questions, a mix or birch & mdf would not necessarily be bad. You would likely never know the difference once it was painted. It is probably a mix of cost, ease of construction & the paint / expansion qualities of the materials that determines what the cabinet maker uses.

With that said - these are your cabinets, and you asked for low toxins/ VOC's. If your builder/ cabinet maker isn't working with you to assure you their methods and materials will fit your desires (or to find alternate ones that do), then I would find another professional that does. Surprisingly, factory finished cabinet lines can have a much better quality finish than "custom" built & painted on site cabinets. It is a controlled environment with less dust, etc. floating in the air. But good quality custom site built cabinets have their perks too. It all depends on the craftsman. Check out examples of their work similar to what you are looking for and see what you think.

Good luck with your project!