Readers of this blog are aware by now of how fashions change in philately. Used stamps were comparatively more popular fifty years ago than they are today. Covers and postal history were essentially uncollected until about 1920, had their peak around 1980, and have since fallen to a secure but niche collecting status. Blocks and multiples were once part of everyone's collection; today a single will do.No change in philatelic tastes though has been more profound than the current affection for original gum on Nineteenth Century stamps. One hundred years ago, collectors were routinely instructed to wash the gum off of their mint stamps. Early postage stamp gums were organically based and prone to bacterial infestation which shows up as "foxing" -those brown stains on the gum and paper which become even less appealing when you realize that they are bacterial excrement. Air conditioning made high humidity less of a breeding ground for these bacteria; so it is a technological change that drove the taste change in philately. In 1920 there was virtually no difference in price for a 1870 US stamp mint with gum and mint without gum. Many collectors preferred no gum as it eased storage problems considerably. By 1960 the difference in price and desirability between the two gum states increased, and about 1990 Scott began pricing mint classic US both with and without gum. The initial price differences were small, but they have been growing every year to where the average no gum Nineteenth Century US stamp catalogs for about 40% of its original gum brethren (and the differences in selling price is even more dramatic).
But original gum mania is merely low grade sniffles for US collectors compared to the full blown fever with which it affects the Italian stamp market. Classic Italy without gum catalogs for as little as 5-8% of the original gum prices. Wide disparities between original gum and no gum stamps are always an indication of market weakness, and the greater this disparity is, the weaker the market for those particular stamps. The reason for this is that there are always a small number of well heeled collectors who want (and, more importantly, are willing to pay for) the best. Market strength is not measured by these wealthy few, but rather, by how many collectors there are behind them, desiring fine stamps but not willing to buy the best. Wide disparities in original gum versus no gum prices are one of the barometers we apply to markets to assess the depth of demand.