- For the beginner, a watermark tray available from most stamp supply sources and a can of lighter fluid available from your local newsagent will get you through most of the watermark work that you will ever have to do.
- The lighter fluid comes in a neat can with a drip tip that precludes spills.
- For safety reasons, don’t pry the cap off.
- Simply place your stamp face down in the tray and add a couple of drops of lighter fluid to the stamp.
- The fluid “wets” the stamp and makes the watermark easier to see. It will also show up many forms of damage such as creases and thin spots.
- Practice first with stamps where you can see a watermark with a bright light and then try harder ones as you become more experienced.
- Make sure that the stamp might have a watermark by looking it up in a catalogue - no point in looking for one if no watermark exists!
- This way you don’t waste fluid.
- Always do watermarking with adequate ventilation.
- Lighter fluid contains naptha which is very flammable.
- In addition, naptha is a solvent and all solvents are to some extent toxic if you breathe enough of them.
- The key to safe use is ventilation and using the minimal amount of watermark fluid possible.
- One or two stamps in your stamp room is probably OK; but when I have to do a lot of stamps, I wait for a warm day and do them outside.
I always work on the assumption that in any case where the watermark cannot be determined, the only option is to assume it is the lesser value stamp.
There's an interesting YouTube beginners video here (in English) from SMCollectibles on how to find watermarks.