Post by Admin on Nov 16, 2014 20:48:28 GMT
What is a watermark?
This was a question I often asked myself when I first return to collecting. I will try my best to explain about watermarks and how to detect them.
You will often hear collectors saying dip a stamp, this is a common term for placing stamps in watermark detection fluid.
A watermark is a impression that is placed on the paper while the paper is still in the manufacturing process, this is done by a number of different ways. A common method was the Dandy Roller used on US stamps the paper would be run through the roller while still wet, this left different thickness or compression on the paper. When held up to light or against a dark surface the watermark would become visible, we will get more into detecting watermarks further in this article.
In philately, the watermark is a key feature of a stamp, and often constitutes the difference between a common and a rare stamp, sometimes the watermark will be inverted, sideways or missing.
So how do you find watermarks on stamps?
Sometimes they are not visible unless you use a watermark detection solution (most collectors including leading stamp expert's use Ronsol lighter fluid) You will hear that lighter fluid is not safe to use, this is true but if you use it in a well vented room you wont be overexposed. I like to do my water mark detecting in the kitchen. This way I can turn on the stove extraction fan and exhaust all the smell of the lighter fluid. This work counter that I use is a large flat cookie sheet with a little lip on the edge, this is handy in case you have a spill, also wear nitrile gloves you don't want any fluid on your skin.
You will need a watermark tray
I don't use the above tray but a black ceramic soap tray I bought at the dollar store works great. The above one has a ribbed side which is designed to allow you to dry the stamp.
Place the stamp upside down in the tray and add a few drops of fluid enough to wet the stamp, you will be able to see the watermark, sometimes you may have to angle the tray and play around with the lighting to see the watermark. You may have to add more fluid. Some times taking the stamp out of the tray using tongs and holding up to the light will help. Once you found what you are looking for all you need to do is place the stamp back into the tray and allow to air dry.
You will see some how to do videos that instruct you to fill up the tray with solution, they are often in the business of selling fluid. A little is more in this case.