"But furniture board = MDF, right?" Not exactly. Some furniture board is actually "partical board". MDF is made up of a very fine "fiber" almost like wood flour. Particleboard/ furniture board (which is more of a marketing term than a product name) is made up of larger particles kinda like grits or cornmeal. The particle size can have a very broad range depending on the maker and the specification. The quality can range from practically junk to a fairly dense and totally waterproof sheet. It ALL depends on the specification, and it's hard for the consumer to tell or compare without getting specification sheets on each product. "Some building people use the term loosely when they really mean mdf." I agree that people use the term but they'd be doing so incorrectly ! "I suppose there could be some MDF that is stronger and more durable than some plywood? " Yes, there are great products in both products as well as crappy ones. comparing a low quality of one with a high quality one of the other just isn't fair. "Frameless cabinets are installed differently than framed ones. You put the whole row of them together, and then attach to the wall as a unit. " This is also not the case. Boxes can be put on the wall the same way regardless of their type. I've seen plenty of "framed" cabinets ganged together on the floor and then hoisted up onto the wall by a truckload of men or a lift like suzanne's first pic shows. Some frameless cabs have a very clever rail system in which a metal rail is attached on the wall and each cabinet is hung independently onto it. There are adjustment cams that raise and lower the box as well as adjust for plumb. You rarely see this on a framed cabinet , but it is entirely possible to use. which brings me to the takeaway: It all depends on who or how the cabinet is designed, and the "frame" is only part of the equation. "Do frameless cabinets require a stonger/better box than than framed ones because of the installation method? " Sort of. It's not because of the install , but rather the design. The frame on a framed cabinet is what gives it strength. So typically, but not always, the sides are thinner to save money. On a frameless, the whole box works as a system to give it strength.

There are several recent threads on this (google search works way better than the site search engeine, just add "site=ths.gardenweb" to get results from only here). Might get more detailed info there. It seems that opinion is split, but my recollection is the pros here use both but don't necessarily recommend paying to upgrade automatically. I don't want to speak for any of them, but in case more of them don't stop by that was the impression I got from past discussions. This also assumes the plywood is good quality (that's a whole other set of threads if you are interested) and the particleboard option is good as both products come in a variety of grades/quality. I'm getting frameless, so consensus is high quality particleboard has an advantage for frameless. I saved the cost of the "upgrade", which even the cabinet guy recommended against.

I love wood, and admire people who are woodworkers. However, I've loved our frameless kitchen cabs of high-density particleboard covered in melamine (interior) and laminate (exterior) for 20 yrs of hard usage. As has been pointed out here innumerable times: - There are different quality levels of ALL wood types. This includes plywood and particleboard. I have in my house different levels of both wood products, because we're book fiends and have acquired over twenty 6' tall, 2 - 4' wide bookcases over the last 30 yrs, to hold huge art and reference books that far outweigh anything I put on my kitchen shelves - and I put a lot, believe me, on my kitchen shelves (I own six different dinnerware services). Our kitchen shelves are infinitely adjustable, and have never bowed or bent. (See the next point for the all-important reason) They have a 75-lb rating for each shelf, whether fixed, rotating, or adjustable. - High density particleboard beats low-quality plywood every time. If you are going to load a shelf up, you should never go over 36" without either a center stile or back wall center support. I personally don't go over 31" without a center support, whether it's a bookcase or kitchen cab (which when frameless is just a bookcase with a door, after all). If you doubt this, take a good long look at the Masterbath cabinet line sold by HDepot, which loves to advertise itself as "all wood - no particleboard!" We bought a few of these framed cabs in 2003 when I was in a rush during a bath remodel. They are the thinnest, junkiest plywood possible. I stand on my kitchen cabs to wash the windows all the time, and I weigh over 200 lbs. I wouldn't dare stand on that bathroom cab! Nice looks, but I've got $50 particleboard bookcases that have proven more capable of holding heavy loads. Particleboard cabs are heavier than plywood. Installers always prefer plywood because it's so much lighter and therefore easier to hang the uppers without as much work. But it doesn't necessarily mean plywood is always better, in and of itself. Again, quality is the determining factor. A custom woodworker (like the one we just had built some beautiful birch plywood custom wall units for us) is going to use something nice s/he can be proud of. A big corporation looking at the bottom line knows that their customers have a price point that works within a narrow range. They know the outside counts for 90% over the insides when people are perusing store displays. - There are different qualities in melamine and laminate as well. The very cheapest melamine is so awful, a damp cloth will ruin the smooth finish and raise bumps that are permanent (we have some pretty, but inexpensive stackable "cubes" that are like this). Conversely, good quality melamine resists moisture quite well - not proof against a long soak, but spills and an occasional dampness won't destroy it. Doubt this? I put my dishes away wet from the DW all the time. I have no idea if the heating element in it actually works, because I've never used it (electricity is expensive out here!). I just shake the visible drops off, stack 'em up and put everything away - no problems after two decades. I do my spring cleaning by spraying the insides with cleaner and wiping them out. Not only are the melamine interiors still perfect, we once had a slow, six month leak in the sink cab from a faulty faucet fitting. It caused a small bubble in the melamine, about the size of a quarter. Raised it up but didn't crack it open. No other damage, then or now. One of the negatives often claimed about particleboard is that if a screw tears out, "it can't be fixed." I always thought that as well, until a contractor corrected me. I have a bad habit of leaning on a door as I open it, and one of our base Lazy Susan cabs eventually developed a sagging hinge from a screw tearing out. Our contractor/handyman filled it with quick-set epoxy, then redrilled the hole and put the hinge back in. Problem fixed, and it's been solid as a rock since he repaired it back in 2003. In summary - buy the best quality of material possible, and make sure the design (e.g., in your case the width of shelves vs load rating) is properly functional.

Something I left off of my last post to another thread similar to this one only asking about Kraftmaid. There are truly differences in the types of each. I would choose furniture grade board over Chinese plywood for instance. I have not checked yet to see if the all ply Mid C cabinets I'm looking at are chinese plywood. Likely they are cause the price is so low! Anyway we missed this at the home expo in March, but my sales guy told me they were there and had a goldfish bowl with both plywood and furniture board soaking for 2 weeks. They displayed it at the expo inviting everyone to try to break the furniture board, and no one could do it. The plywood was a total mess. It just depends. Whatever you get make sure it's the best quailty and I would think you'll be fine. I noticed for instance that the KM furn board was thicker and appeared to be better quality than the Mid C furniture board.