I worked as an engineer for a company who built about 250 high end cabinets at that facility per day. Most of the cabinets that came from that line were plywood sides, either 1/2" or 3/4". I became rather biased about it, and looking back, it was probably unjustified. To me, the important parts of cabinet construction are the face frame, the joints, and the back either being decent thickness or having nailers for strength were they are joined and also attached to the wall. This is just my opinion, but even though the plywood makes a very solid nice cabinet....Once it is installed, and forever more, no one will know the difference. The plywood does make for a bit more attractive interior, but probably not enough difference to speak of. Maybe in instances where a finshed interior is important, then plywood, or actually wood vanier sides are required. Of course you can vaneer partical board too, and then you still can't tell the difference once installed. I still have a bias toward plywood ends, but it probably isn't a logical one. More cabinets are made with furniture board sides than plywood, and there really aren't problems with them.

Thanks for the input! I think you're right about once they're installed I won't tell the difference...I feel that way about a lot of things in the kitchen these days! Do you know what furniture board actually is? Thanks!

furniture board - maybe MDF of some sort?

There's different levels of quality in all types of wood products. I'd ask to see an actual sample of a cab, preferably one that's been cut on the diagonal so you can actually see the inner construction materials.

We have laminate/melamine covered particleboard frameless cabs, and have been extremely happy after abusing them for 20 years. They are still in great shape and solid as a rock. But I knew they were very high-density particleboard; I'd seen a cut-away cab sample.

Having been a book collector for 40 years, we have over 20 particleboard bookcases of varying quality (that's all a frameless cab is, really). The good ones are very good as long as you don't span over 32" without support. The bad ones are indisputedly and always, junk.

Now they use MDF, but again, there's different quality levels. Even plywood can be junk level - examine Home Depot's Masterbath cabinets sometime, we own some and the plywood is truly surface-pretty but structurally wimpy. Your cabs are one of your biggest costs in a kitchen remodel, so do as much research as possible.

We have DuraSupreme Crestwood cabinets with the furniture board sides as well as a couple of cabinets that had to be ordered in their custom line with plywood sides and interiors. I can't tell any differrence in quality between the 2 cabinet lines. The Crestwood cabinets have a veneer interior that is very good quality. All our Durasupreme cabinets are very good quality and the few problems we had with mis-shipments were promptly corrected. Our cabinets are Knotty Alder with a wheat finish and coffee glaze and we also have an island in distressed black paint on maple. Very happy with all.