We ordered these cardboard sheets for packaging art prints to sell. They are lovely sheets of cardboard. Flat. Square. Brown. Approximately 1/8" thick. They worked great for packaging art prints, except for one small problem: 10 of them were too damaged to use. If I mention how they sustained this damage, this review will not be published (ask me how I know!), so I will just tell you they were not damaged in transit but rather by something that rhymes with "smackaging." This faulty smackaging caused 20% of the cardboard sheets to be bent, creased, and unusable.Now, you may be asking yourself, "Why the four-star rating if there was a smackaging issue that damaged 10 of 50 cardboard sheets?" Well, I will tell you. I originally wrote a two-star review which (apparently) violated this website's comment policies. It seems corporations are not bound by the First Amendment and do not have to grant their reviewers freedom of speech or the press. Instead, they make up vague and arbitrary rules like: "You are not allowed to talk about the seller or the shipment! You are only allowed to talk about the product! Even if the seller uses a type of packaging that damages the product! Just tell the other customers about the damaged product but DEFINITELY DO NOT mention how it came to be damaged!"Anyway, I digress. With my attempt at leaving a two-star review thwarted, I just settled for the boring option of contacting a party which shall not be named but possibly rhymes with "the speller." This unnamed party was very responsive and granted me something that rhymes with a "dull defund," which I was not expecting. I will probably reorder these beautiful cardboard sheets next time we need to package some art prints, in the hope that this speller has its smackaging issues resolved.Bottom line: four stars for my overall experience with these cardboard sheets, and zero stars for censorship. This is America! We should have something that rhymes with "speedom of bleach!" Even if it's just to complain about smackaging.Three things about these cardboard sheets (review: January 20, 2021, 30 count, 24" x 36" sheets). First: they were properly packaged -- all 30 sheets were in very good condition (a few snubby corners, but all sheets still quite usable). The smackaging was good! Second: they arrived quickly -- in-hand 3 days after ordering. Third: they are expensive. All-in-all, a thumbs up!other reviews are true, the binding strip is too tight on the cardboard inserts and warped about 5 pieces. I put these in padded envelopes to keep my 11X17 prints from bending during shipping. so if there is a kink in the cardboard, there will be a kink in the print, kinda undoing the whole reason I bought them.The undamaged ones are just fine though and keep my prints flat with no bending or damaging, just wish if I was paying for 50, that I could use ALL 50 of them.This is a great product as I use these for shipping photos to not get bent. These are thick enough to use one with the addition of acid free cardboard backing I use in the photo bag with the photo and they hold up well. If you do not have the added backing then 2 would really protect what you are sending. I have used other products on Amazon at very similar price and even with 2 you could not protect anything while shipping. These backings by Paper Mart are just what i needed. Ordered twice and will continue to order as long as they remain the same.These work like a charm for organizing your fabric stash. I was able to put from 1 yard up to 5 yards on one piece and have it look great. I do think they are a bit expensive but I will be able to reuse them as I use the fabric. Most people probably don't have as much fabric as I do so that would not be as much of an issue.I'm using these to protect comic books mailed in envelopes, and they seem to work fine. They have the corrugated lines going the short way so they may bend a little easier than those with the lines going lengthwise, but they are thicker than one's I've had before which were lengthwise corrugated, so that balances out. They're a little shorter too, but still longer than any comic book, so I've had not problems so far.These are packaged great so they come in pretty much perfect condition! I use them for inserts to stiffen packages I mail but they would work great for craft projects too since they come packaged correctly!I was planning on using these as backer board for artwork. I can use about half to 2/3rds of them. The rest have been pressed or squeezed tightly by the strap that keeps them together that boards on both ends are unusable. They've also been roughly cut so they don't have a neat appearance when combined with your art. I would not advise using them for this purpose but simply as inserts to keep your mail from bending.