Any Substitute For Watermark Fluid ?

I always have two curious cats helping me with my stamp collection.
Is there any technique for detecting watermarks that doesn't involve watermark detection fluid or lighter fluid ? Has anyone had good luck with any alternative method ?

A really strong back light? Just soak in water and then scan?
Don

Keep some catnip on the floor to sidetrack them from the desk. That's what I use to keep mine off desk. Also a few catnip toys to throw for distraction.

Don,
I never thought about just soaking in water and scanning. I'll have to try that.

There is a device called a Signoscope from SAFE.
Depending on the stamps you're viewing, it ranges from poor to great. US single lines can be hard to see if faint, double line usually are fine.
Watermarks from other countries that tend to be heavier, like UK and Canada (as well as others) work really well with it.
I have used mine off and on over the years. But overall I would say, there is no substitute for lighter fluid... some watermarks are extremely tough to see (particularly yellow and orange faced stamps, like 10c Washingtons). You won't be able to find the water mark on these without fluid.
Lock your cats up while you're checking for water marks... shouldn't take that long...

If you have a flatbed that can do film negative scanning, you could try this method. It doesn't work for everyone, but I've had decent luck with it.

Lock them up. LOL

Too much footing around and you will eventually end up with a valuable stamp with additional perf hole in it!

Edit: wow, did not expect that censor.

I remember starting out in the 50s and 60s and buying a bottle of Carbon Tetrachloride for watermarks. I imagine that's impossible to get anymore. It never seemed to affect me

I love cats, and they're living proof that the earth isn't flat. If it was, our kitty friends would've knocked everything over the edges by now

Thanks for the watermark alternative Don. Im not saying inhaling the lighter fluid fumes while identifying Franklin and Washington heads on the stampsmarter site was a bad time but this method sounds much better.