Tarnished Gold Overprint on Early Saudi Issues

I was referring to the color of the stamp as described in Scott, not actual make up of the ink. I forgot to mention these are all in used condition without gum, which may have contributed to tarnish through contact with water. If there is a way to get rid of tarnish without damaging the stamps, I don't see it any different than washing used stamps to clean up what can be cleaned up. Most collectors wouldn't have a problem with it.

From what I remember tarnish removal involved holding the stamp over some kind of vapor.

Do you have a link to any article that describes this tarnishing as normal? I am planning to sell these stamps and this would help if I leave it as is.

BTW, I am a dealer.

Hi
Kingdom of the Hejaz
Stamps of 1917-1918 Opt in Black red or Brown

1921
Scott L14 - L19
All values except L15 exist with Gold Opt

The ethics of cleaning Postage Stamps, (and coins)

Tarnish (Oxidation) ....a consideration

The France 2008  "Marianne" postage stamp  (5 Euros)
99.9% pure silver
A real pressure sensitive postage stamp

It comes on a collectible card, which is sealed to prevent oxidation (Tarnish)

Brilliant !   Thank you. salentin
Info saved.

I share your mixed order, I have always had Hejaz  separate, perhaps from my early Gibbons days? 
I have my Saudi Folder now named  "see also Hejaz"

It's so nice to have queries solved.

In defense of my statement and in the context it was made, most collectors will not have a problem with washing used stamps, that's how they come off paper, so do some stains, dirt and grime that was on them. I drew a parallel to removing tarnish from this overprint and stated I (not most collectors) consider it the same. Not a broad statement at all.

Altering stamps to create varieties wasn't even in the realm of this discussion.

Hi, Lenny (almazstamps), and thanks for your post.

Discoloration of stamps, or in your case overprints, can be due to different factors.  There is a thread about discolored stamps here:
thestampforum.boards.net/thread/5698/causes-stamps-discolored

One of the commonly encountered causes of discoloration on stamps is sulfuretting, also called sulfurization (sometimes referred to as oxidation, but that is an incorrect term). Discoloration of stamps due to sulfuretting comes about due to exposure to sulfur in the air.  Fortunately, the discoloration can generally be remedied by soaking the stamps for a few minutes in a 3% hydrogen peroxide solution.  That treatment doesn't always work, but it often does, in my experience.

The discoloration is caused by metal constituents in the ink reacting with sulfur in the air.  In the case of your gold-colored overprints, I could imagine that although they likely don't contain any real gold, they may have some metal content in the ink, and it is that component that is giving rise to the discoloration.  This is, of course, only a theory, and just my opinion.

If you do decide to try to clean these stamps with peroxide, I would suggest trying a small test first on the least valuable of the stamps.  You could use a cotton swab dipped in the peroxide to apply just a bit of it to the overprint and see if it appears to make any difference.  If it seems OK, you could try soaking.  TSF member Stan (stainlessb) is very knowledgeable about peroxide soaking, and a study that he conducted generally showed that it was safe to soak classic era stamps up to 10 minutes in 3% peroxide.

That said, my recommendation would be that if the process seems to help, I would soak the stamps one at a time, keeping a close eye on each stamp as it is soaking, and as soon as the discoloration is removed, the soaking should be stopped.

Just my opinion, and of course, others are welcome to agree or disagree. Hope this may help.

Big thanks to Berrylium Guy and Stan. Very informative. I think that's what I read long time ago but couldn't remember. I don't think this is the case with my Saudi Stamps, but I do occasionally encounter sulfur caused discoloration, although rarely.

I have a method of washing stamps with fugitive inks. I carefully float the stamp on water surface, making sure it's not fully immersed and doesn't curl. If the water is at room temperature the stamp will not curl. Nothing is guaranteed 100%, but it protects such inked stamps and allows removal of gum remnants.