I'm Trying To Find A Good Light Source To Detect Taggant On Stamps

So, I've tried to do this on my own but I keep getting nowhere. I've tried a blacklight bulb or two, but no glow of tagging on stamps known to be tagged. Shopping Amazon turns up a lot of assorted types with light of differing wavelengths.

I don't know what I should get!

I want something which will detect the various taggant in both United States and worldwide stamps.

Do you have one that works well at detecting tagging? That didn't cost an arm and a leg? If so, please share what kind it is, where you got it, any specs which might be relevant to find different products with the same characteristics, stuff like that.

I've always wanted to detect the tagging on stamps, and now that I'm actually trying to do so, the light source is proving quite elusive.

Josh

Which type of UV light you need depends on what you collect and why.

For USA you need a shortwave UV light, 254 nm. Works for Israel, too, I believe.

For most of the rest of the world you need longwave UV light, 365 nm.

If you collect Great Britain you need both, they switched from 254 to 365 sometime in the last 40 years.

The longwave UV is also very useful for older stamps that do not have any taggant. Some printings can be identified by the glow of the ink. The light can also sometimes discover repairs or other defects.

The blacklight bulbs you bought are longwave. They are generally safe to look at the bare bulb. Shortwave bulbs are shielded because you should not look directly at them.

No. 254nm light thingies also emit light up to the visible range. A filter is placed in front of the glowing element to get rid of most of the wavelengths above 254nm.

If you want a cheaper lamp, here is how it looks like

Of course this requires some work and Chinese suppliers. these handheld 4AA battery thingies are ok for checking, but not good enough for photographing stuff.

It's not portable or always available but I find mark1 Sunlight works as well as anything for detecting Phosphor tagging. Hold the stamp towards the sun shines so It strikes the stamp at a shallow angle. look at the stamp atsomethimg around a right angle to your eye then move the stamp around gently until all of a sudden the phosphor tag will show like its a different color almost. AAAAAAAAAAAT first it never seems to work then suddenly one day you can see the tag and after a while the tags become easily seen.

It's certainly true that with surface block tagged stamps, the taggiant can more or less easily be seen without any lamps. When it comes to overall tagging and particularly prephosphored paper stamps, you are often out of luck without a lamp.

I use the cheap chinese SW UV battery operated units all the time to take pictures of tagged stamps. I use my iPhone and they turn out fine.

If you want a higher powered portable SW UV unit Ultra Violet Tools (uvtools.com) sells an 11 watt version. It costs a bit more, between $80 - $90, but it works great for sorting the large piles of stamps.

These are the UV lights I regularly use for tagging. The top one is a Lighthouse (Leuchtturm) short-wave light for checking most tagging on U.S. and some foreign stamps. The bottom one is a long-wave light from Amazon to check the tagging on some modern U.S. coil stamps.

If you don't have the filter attachment for that Lighthouse shortwave UV light it leaks a lot of longwave light which can affect what you see.

Totally agree with eyeonwall. I tried the SW one shown just to see what it would do and it doesn't show tagging on US stamp very well or faintly at best.

Mark, don't you use the powerful UV Tools model for SW.

Yes I do and It works great from sorting bulk material.