Well, firstly, there are many, many worldwide self-adhesive stamps that soak off paper just fine. The self-adhesive stamps of most countries in Western Europe - Germany, Switzerland, Netherlands, Scandinavia, etc, - soak off with no problems whatsoever - even ones being used today. There are, however, many that aren't very soakable - Certain stamps of Ireland, the UK and Spain come to mind. Australia is difficult but they can usually be coaxed loose in water. There's not really a hard and fast date, but around the year 2000 or so seems to be when S/A stamps started to take off, and after 2005 or so their use was more or less the predominant (though not necessarily universal) type of adhesive in most countries. If you soak enough you'll kind of learn to spot the problem stamps ahead of time and use something else to get them off paper. The "problem" stamps are mostly confined to certain countries and you'll learn to look out for them.
I've soaked at least 15 pounds of kiloware in the past year, probably half or more of that (by weight) has been self adhesives. I bet if I pulled out all the non-soakable ones out of that, I'd have come up with no more than an ounce or two. Seriously, for most countries the type of gum or format isn't the issue it is with US stamps and they soak just fine. Again, there are certain countries with a lot of non-soakable stamps, and if you just happen to have a whole batch of them, you're experience will be totally different. But assuming that's not the case, I'd honestly just get busy soaking. |