The history of philatelists mounting stamps in their albums has four phases and does not really represent progress. The earliest stage, beginning about 1850 when people first began collecting stamps, to about 1880 was the period where stamps were simply gummed down in albums. If the stamp was mint, the gum on the back would be wetted and for used stamps a paste or glue was added. This was a quick method of mounting, but far too permanent. As collectors began to trade and sell their stamps more often the most common mounting method changed to using gummed selvage or slips of paper to hinge stamps. This method was the dominant mounting solution from about 1880 to about 1920. Stamps could be taken in and out of albums but the gummed selvages stuck too well and could not be removed without soaking them from the stamp. This was inconvenient for used stamps but damaged mint stamps which collectors wished, by 1920, to collect with full original gum.
Gummed glassine hinges were the answer and the gummed hinges of the 1920 to 1970 period were the most efficient solution for stamp mounting that our hobby ever devised. They were cheap and, beginning with the Dennison hinge after about 1950, highly peelable, leaving only a trace of a mark on mint stamps. But even this trace was too much for increasingly quality conscious collectors who now demanded plastic mounts that left their stamps perfect. The problem with these modern plastic mounts that are in use today are two. First they are slow to use. Experienced collectors could hinge several stamps a minute into their albums with peelable hinges versus perhaps one or two with modern plastic mounts. But mostly, modern plastic mounts are expensive. A pack of 1000 hinges cost 25c(say $1 in today's money) versus $5 or more for a modern plastic pack of mounts that can mount only a couple hundred stamps. At a few cents a piece for the mounts alone, most stamps of the world aren't worth mounting and it is the mount cost factor more than anything else that has contributed to the decline of worldwide general collecting.
Gummed glassine hinges were the answer and the gummed hinges of the 1920 to 1970 period were the most efficient solution for stamp mounting that our hobby ever devised. They were cheap and, beginning with the Dennison hinge after about 1950, highly peelable, leaving only a trace of a mark on mint stamps. But even this trace was too much for increasingly quality conscious collectors who now demanded plastic mounts that left their stamps perfect. The problem with these modern plastic mounts that are in use today are two. First they are slow to use. Experienced collectors could hinge several stamps a minute into their albums with peelable hinges versus perhaps one or two with modern plastic mounts. But mostly, modern plastic mounts are expensive. A pack of 1000 hinges cost 25c(say $1 in today's money) versus $5 or more for a modern plastic pack of mounts that can mount only a couple hundred stamps. At a few cents a piece for the mounts alone, most stamps of the world aren't worth mounting and it is the mount cost factor more than anything else that has contributed to the decline of worldwide general collecting.