Watermark Detection Fluid

Will watermark detection fluid (Prinz) damage the gum on mint stamps?

No - although most of us probably use lighter fuel, which is cheaper.

Ronsonol is my preferred lighter fluid

The problem I have with watermark fluid is that it evaporates so quickly that you hardly have time to really look for hard to find watermarks. Lighter fluid evaporates far slower giving you a better chance to find a watermark.

I use lighter fuel but the ingredients include Light aliphatic 0.1% which is grease. So I managed to beg a100ml of Anhydrous alcohol from someone at a local university laborotory.. I agree the slower evaporation speed of lighter fluid is an advantage over the Prinz product. I have never met anyone who has detected damage to a stamp from using lighter fluid.

I use Clarity but I splurged to get a pricey Lighthouse water mark detector off ebay. The advantage is there is no evaporating fluid but requires stamp to be hinge free since it affects the ability to get stamp flat. I did it because I am a worldwide collector and not familiar with all watermarks so takes time to find hard to see when stamp is in less than perfect condition. It has worked when fluid did not but also fluid works better at times.

Yeah, using watermark fluid like Prinz can sometimes mess with the gum on mint stamps. Even though it dries fast, it can still change the look of the gum, maybe making it a bit dull or less smooth—so it might affect the value if the gum condition is important. If you're dealing with a valuable stamp, you might want to be careful with it