So the bottles are made of glass. The caps are made of plastic which have been chrome plated. The caps are actually better than I think some reviewers let on. Mine seal just fine. The caps are a bit flimsy but not so bad that I cant tighten them down or feel like they will break in my hands. The glass bottles are quite sturdy. The one thing that I did notice which made me a bit nervous was that, if you fill these bottles to the top or near the top with a spice that has any amount of substance to it (i.e. salt or pepper or any powdered spice) the bottle starts to get top heavy and begins to lean forward out of the rack appearing as if though they will slide off the rack and tumble down onto whatever is beneath them. That I found somewhat concerning. Mine arrived with each glass bottle individually wrapped in cardboard. The packaging was fine. Everything arrived in one piece.That being said this part isnt a reflection on the product as much as it is the seller: CHEF'S CATALOG. As of Oct 1rst 2012: I knocked their seller review because the product did not arrive on time. In dealing with their customer service I found they were quite rude and didnt seem to care they missed the delivery date and attempted to blame amazon for it. Amazon does not sell or fulfill this order. The order goes straight to Chef's Catalog and they ship it. If you order from them and pick standard shipping (3-5 days) the package will be late and Chef's Catalog will tell you that their standard shipping is conveniently 7-10 days (shipped via Fed-Ex or USPS [mine was shipped USPS]) which is a really long time in my opinion. Also when you get your package it will be filled with coupons for other websites and a cheesy catalog from them that has QVC type products through-out it. Also expect to get a ton of junk mail after ordering from them.After reading all the reviews about all sorts of different spice ideas, and looking around in stores for months, I found out that some details are very important, and I'm really pleased with these bottles and racks.1. The bottles need to be close to the standard size of most spice bottles so you don't waste spices when you're filling them. These are the right size.2. The opening needs to be large enough to fit at least a teaspoon measuring spoon into. These are.3. The bottles need to have little shaker thingies as options. Also, it is helpful if some of the standard bottle sized shaker things (holes in the top, with the little flap that opens so you can pour a spice out as an option), from some of your old bottles, will fit. Most of them did on these.4. I like having the spices laying horizontally with the labels facing out, because it's a lot easier to see them than having to move a lot of bottles around and reading labels on the front. Also, they are just below eye level now, rather than up in a cabinet where I have to rummage around on my tiptoes or get a stool.5. Speaking of labels, I ordered some from Amazon as well, round clear ones (set of 100 and they were dirt cheap). Eight blank ones were included, and there were about 60 spice labels, and then some other household labels. These fit perfectly on the tops of these jars.6. I know everyone's cabinets are different, but I have one cabinet that all three (I ordered three racks) fit on at eye level, so I can easily see the labels. That's right, fifty four spices in one eye level cabinet, all neatly stacked and with all labels showing! It's terrific.Finally, I was very pleased with the price and quality. These are nothing fancy, but the tops screw on well, and the bottles feel solid. I even dropped a couple of them as I was filling them and they didn't break, though I wouldn't recommend trying that out!I got so inspired that when I realized I had about six bottles left over, with some unusual spice names on labels, I just got on Amazon and ordered the additional, more exotic spices to complete the collection. Things like saffron and anise seed, and some dried herbs that I grow fresh, but it would be nice to have on hand in dried form. Anyway, I am SO pleased.I love it! I want to cook something right now!If you're like me, and have a ton of spices taking up a lot of cabinet space in a disorganized mess, then this is the answer for you. All of the jars are nice glass with chrome plastic tops (I've uploaded a picture). The chrome rack holds all of the spices with no problems. It also takes up minimal counter space and looks nice. Now to debunk some of the issues people have with this:SEAL - I've had no problem whatsoever with these jars sealing. Yes, the lids are plastic. And? I think you could probably over-torque them if you were trying to tighten them way too hard. But I tightened the lids very tight and they work just fine. I also tried the water test that the main review on here said, where they put water in one of the jars, sealed it, and water ran right out when turned sideways or upside down. Not the case (for me) AT ALL. I tried the same exact thing and a single drop didn't come out.SHAKER HOLES - Yes, as many reviewers mentioned these jars only come with plastic shaker tops that suit more granular spices, like paprika for example. Yet if you're filling them with, say, crushed red pepper, you're not going to get anything out of them with the small holes. The solution is a simple singular hole punch. Just like the ones used around the office or school for papers. I picked one up at the local office store for 2 bucks. It punches holes in these shaker lids no problem. And they are the exact size of the bigger spice shaker holes. You can also punch holes as you see fit, adding more or less holes for the particular type of spice.LABELS - While at the office store I also picked up some Avery 5422 multipurpose labels. These fit the jar lids almost perfectly, with just a tiny little bit of overlap which I actually like. You can use these with a computer and make custom labels, custom font, and have hundreds of labels for so many other things. All for around 5 bucks.I really don't see how you can go wrong with this thing. It organized all of my spices, opened up space, looks great, and it's not expensive at all! If you need to organize a large collection of spices that you can't even see all of while cooking, look no further. This is the answer for you.The lids are flimsy plastic and the bottles are NOT air tight... Spices go stale when not kept air tight..I thought I was sacrificing enough in quality because I was going with clear bottles where the light can reach the herbs (not good), but the general quality of this product is not up to speck for my kitchen and cookingSturdy rack and jars. Look finished off with labels I bought separately. Blends in well with other kitchen utensils. Good value for money.After buying one of these and finding the frame and glass bottles were decent quality and did the job, I ordered a second but that wasn't as good. The frame was slightly twisted with the result it won't sit completely flat on my work surface and rocks a small amount when touched. I didn't bother to return it as it still does what's required and the jars are still secure, but it was slightly disappointing it wasn't as good quality as the first one.I love this - but could have done with another row! I had a square, plastic cake box containing 25 assorted herbs and spices in non matching bottles cluttering up the bottom shelf of a kitchen cupboard. Finding the correct spice was a matter of guesswork accompanied by curses! Spotted this whilst ambling through Amazon, as one does, and ordered it on impulse. So glad I did. I can find anything at a glance now and I've room to put overstocks and refills behind the rack, out of sight. Excellent solution.