Pushing 330,000 All Different Worldwide Stamps In One Collection .

Mounted collections - do command a premium. You are paying for the work that someone did to organize and identify the stamps.

Love seeing one pound value stamps... always catches my eye. I have found very few people can use mounts correctly, very often the middle of the stamp gets stuck to the page... How often do you remove the mount only to find out that the stamp was previously hinged!

I think stamp dealers and auction firms that are viewing a collection , once they see that hinge stamps were put into mounts ,they quit checking the rest of the collection and start discounting the value of the whole collection as hinged .

It also holds true that stamps after 1970 are not being identified as hinged or mint never hinged ,the auction firms are just using the date that the collection is up to like " 1857-2019 " leaving the bidder to guess are they hinged or MNH stamps .

You only stick stamps in mounts to the page if you use split-back mounts. So many collectors don't know how to use them.

"split-back mounts. So many collectors don't know how to use them."

Too many think the more slobber the better

Yes, many collectors don't know how to mount split backs. Only wet the top very lightly. However even more people don't know how to hinge. For every one poor stamp mount, there are 9 poorly hinged stamps. Most thins are caused by poorly hinged stamps. On top of that, I have seen stamps with 3 or more hinges attached to the back. I would rather see a MH in a mount than re-hinged with a second hinge. Hinges are responsible for so many damaged stamps. Hinges can also leave a hinge imprint on the stamp. The worst thing with mounts is some collectors are so anal, that they have to squeeze the stamp into the mount. Years later, all you have is a warped stamp as paper contracts and expands. Plastic also contracts and expands. They thought there were protecting the stamp, but they were really damaging their collection. Lesson is to learn to properly hinge or mount a stamp.

yes, they tend to over wet mounts too
plastic tends to only shrink
another thing I see is stamps taken into an out of tight mounts enough times develop shorter perfs on the top as the perf fibers wear off

Agree with Dragon about hinges. On feeder albums I acquire, typically huge amount of stamps are damaged by hinges. It is worse on newer albums where the collector used non-peelable hinges with way too much slobber. Also lots of mint stamps are damaged when hinging and get stuck down by their own gum. For this reason, I pretty much mount nearly all mint stamps, even MH.

The best way to hinge is to use moisture sparingly on old Dennison or Fold-O-Hinges (really most 50s - early 80s era hinges work fine) Then the most important lesson, after you hinge, wait a few seconds, then gently lift the stamp up from the bottom with your tongs to make sure the stamp does not stick to the page. Agree about people over-hinging! Also avoid extreme pressure to the pages to avoid the hinge-print problem. Don't pack in those pages...
Hinge like you will be the one to someday remove the stamp!

More times than I could ever remember. And what's worse is when you ask sellers to confirm that at least the high value is actually MNH, sometimes they become defensive and toxic. Why do so many sellers assume a mint-appearing stamp placed in a split-back or fully sealed mount is MNH? It's just pure laziness and a lack of honest professionalism.

The question being discussed about mounts that drives me nuts and is true for a lot of problems is ---- you just don't have the correct size of mounts ,I am sure others have this same problem . Too many stamps have goofy sizes . I have about 10 different sizes in seperate envelopes and sure as can be expected the size I need isn't on the table and to search for the next size and start cutting down mounts . Then everybody already knows I can't cut in a straight line or edge for a proper looking mount . Life goes on . .

Only 10 difference sizes for mounts? That's not nearly enough to cover the entire world.
What annoys me is when one stamp in the set has slightly jumbo margins and won't fit in the standard size mount. Either I use the next-size up for the entire set, or that one stamp uses a slightly bigger mount, which stands out, and not in a good way.

If I buy mounts, I just buy strips in a couple of sizes, which, when cut appropriately, will cover most stamps. Specific sizes and bad fits are only a problem if you use split-back mounts, which I prefer not to come into contact with.

I just make sure the stamp more than fits into the mount. Always go bigger.

If you really need a lot of different size mounts the best place and the best price is to buy them from a major auction house . It seems a lot of collectors drop dead with at least a shoe box of unused mounts . Kelleher ,Rasdale and Dutch Auctions usually have them up for auction .