PF / PSE Tools For "Regummed Over Thin"

Hi All - I recently submitted a stamp to PF that came back "regummed over thin". I was curious what type of tool or instrument is used to detect that. Is it simply dipping in watermark fluid or is it something more sophisticated?

Related to this, I notice in the PF database that the number of dollar value Colombians " regummed over thin/crease" is crazy. Where do re-gummers get the gum? Is it washed from stamps of that era and reapplied or is it something more common. The stamp I submitted looked amazingly good - no glue on perf tips or in holes.

Canyoneer ---- It is more Sophisticated.........it is called common sense .

First is getting the right equipment .
If I am going to test a $5.00 Colombian , I need a few copies of the 1 cent ,the two cent and maybe a few other low values both mint and used . Common sense tells me all the stamps ,all my cheap stamps and your $5.00 were printed in the same room with the same machines ,that means same size ,same paper ,same perforation machine and the same glue machine .

Lets address what you wrote ---the glue between the perfs can be removed if you buy a Dremel electric drill at the hardware store . Also buy the rat tail drill bits ,these are tiny drill bits that fit into each perf hole so you can have nice clean perforations .

Remember each Colombian stamp is the same size perforated on the same machine by the same guy . So if your $5.00 is smaller then it was recut to give the perforations a clean set of teeth . Makes sense a reperforated stamp is smaller .

Next area is the color of the gum -----Have your wife go to the store and buy 8 or 12 different boxes of Tea this way we can tint the glue color to the same as the original glue ,you need a good color match .

Next area is glue thickness {this is a area I have expertise , I worked at Hoener -Waldorf Box Factory and applied hot wax to boxes for shipping meat } You can control the thickness of wax or glue by adjusting the heat ,the hotter the setting the thinner is the layer of wax or glue . Also it was applied with rollers ,don't use a brush , Use a roller devise to give a smooth layer of glue .

Next this is where they caught your stamp , You need a light table ,that is a table with a adjustable strong light under a flat glass table . Lay all those cheap stamps plus your $5.00 stamp upside down . The stamp with the thin will show more light passing thru ,while the other will be uniform in passing light ,you can see the thins.

Often thins that have been regummed will be filled first, and dipping will show that clearly. A lot of examining a stamp properly involves being taught what to look for. Over time and experience (which always involves looking at a lot of stamps), one learns what should or should not appear on a given stamp.

These were concerns I have had for a long time and just chose to ignore. Now I see that my instincts were right and I will save my energy for when I have strong doubts on pricier items.

It should be remembered that regumming stamps is not simply a new or recent phenomenon, but has been going on for many decades. So what materials have been used can depend on when it was done, and how skilled the perpetrator was. Plus gum can be "redistributed" as well.

Since CV for regum is same as no gum, I'd prefer no gum. Regummed status adds a level of uncertainty with regards to unseen faults.