As you get into stamps, you are going to find that many issues of stamps exist printed on watermarked paper. Not only that, but often the same stamp will exist with 2 or 3 different watermarks, and the stamps will also exist with the watermarks inverted, sideways, reversed, sideways inverted and sideways reversed. In many cases, the differences between these varieties in terms of value can be significant.
So, it is important to acquire the equipment to be able to detect watermarks accurately if you are going to collect stamps from the British Commonwealth early United states before 1920 or most European stamps issued before the 1960's to name just a few. In fact, most countries' early stamps have watermarks. Canada is one of the few countries whose stamps are generally not watermarked.
So what are your choices? What means can you use to detect watermarks. Well, you have four options:
- Use a black watermark tray and watermark fluid to reveal the watermark.
- Use a black watermark tray with no fluid.
- Use a Morley-Bright ink satchet detector to reveal the watermark.
- Use a Signoscope unit to illuminate the watermark.
The cost and effectiveness of each of these methods depends on the type of stamps you are working with. There is no single method that works perfectly with every type of stamp unfortunately.