What Causes Stamps to Become Discolored?

Chris, you are right. The liquid the dealer was talking about was probably Hydrogen peroxide. There are some threads in other forums informing about good experience on using this liquid for bringing back the original colour of stamps. It can also be used to some extent for reversing negative effects on stamps stored in hot climate and/or very humid conditions. In some of the experiments shared, the improvement in colour is unbelievable. Probably not worth the effort for the more common 'Germania' stamps tough.... but the common stamps are great for experimenting.

Thanks again to Nelson, and his extensive philatelic library, we all now can benefit from those resources and learn a bit more about some of the finer points of the hobby we all love.  One thing I have learned is that when Nelson offers to share some of his library treasures, don't hesitate--get whatever it is while it is on offer.  It will always be worth it!

An important aspect of my working career has been engineering.  While I have also worked in other roles during that time, I am at heart an engineer.  I like technical things, and I have been involved in the writing of many technical papers, and when I do those activities, I strive to be as technically accurate as I can.  It is one of the aspects of my character that as my wife would say, is "both a blessing and a curse."

So, I have read the first few pages of the reference cited and offered in Nelson's post, and I have had a couple of realizations.  I got the technical terms in my own previous post incorrect, so for clarity, I would like to correct that now.  I will also go back and edit that post, for the sake of others who may access this information in the future.  So according to the reference:

"Deoxidation is synonymous with Sulphuration (Sulpheretted) and is often misinterpreted with oxidation. A sulphuretted stamp is one in which the lead in one of the ink constituents has combined chemically with the sulphur in the atmosphere. This causes the original colour (usually blue, green, red or yellow) to become a brownish black colour. Salt ocean water can often achieve sulphuration."

In summary, what Andy (ajkitt ) found in his stamp is, therefore, not oxidation but rather deoxidation or sulphuration.  As Jon (blaamand ) mentioned, the process of using a liquid like hydrogen peroxide to reverse that process makes sense to me, at least in terms of the chemistry.  And that process would oxidize the stamp to reverse the deoxidation which occurred.  This also fits with what the dealer was trying to explain to me in French, but which I did not understand well at the time.

He was saying something that sounded like "oxygen-rich water", and I was thinking what could that be?  But of course, as soon as Jon mentioned hydrogen peroxide, I thought "of course"!  How could I have missed that?  The chemical formula for water is H₂O, and for hydrogen peroxide is H₂O₂.  Oxygen-rich water it is!

As I work my way through the rest of the reference supplied by Nelson, I will make additional posts to this thread, if they seem relevant to this specific discussion.  Steve (Admin ), should we consider renaming this thread to reflect that it is about sulphuration and oxidation of stamp colors, and relocate it from the Germany board to a better location as a reference for others?  To that end, I am also planning to post scans of other sulpheretted stamps, and I may attempt to try some of the processes suggested in the reference.  Just a thought....

Thanks to all for reading my ramblings!

I don't know of one - I've posted a few screwballs in the past (like this post showing a couple of oddities from Brazil) but generally in the correct country page or some other thread that was specific to some discussion that was already underway.  Oh well.  Go ahead and start a thread, then there will be one!

And in that regard, there are also things I've posted in the past that I can't find, and here's one of them which kind of sort of almost fits in with the current "discoloured" theme.  How did this happen?  Is it an actual albino (mostly, there's a little bit of ink remaining on the design) or has somebody figured out how to remove the stamp design ink without removing the precancel ink?



Ryan

Thanks for your post, Ryan!  As it happens, at this point, I think that I may be able to answer your question.

I double-checked, just to be sure, and the US 6-cent Garfield definitive was originally printed as a red orange stamp.  In fact, I am sure that I have some pretty deeply orange colored examples of this stamp back in California.  Noticing a color theme here?  Despite the fact that Nelson's reference mentions that several colors may exhibit signs of discoloration due to sulphuration, it certainly seems from this thread, that orange-colored stamps are especially susceptible.

First the German stamp, then my French stamp, and now your US stamp, all are orange in original color.  The dealer here in France told me something about using hydrogen peroxide to restore the orange color on these stamps.  He said to be very careful with the amount of time the stamp spent in the peroxide, because if left too long, the color would dissolve and disappear completely.

Ryan, I think that that is exactly what happened to your stamp.  In the upper part of the stamp, there is still a little ink remaining, and what is there looks brown, not orange.  So, my guess is that your stamp was sulphuretted and then put into a hydrogen peroxide solution to try to restore the orange color, but was left long enough that the ink dissolved altogether, leaving your albino result.

This is just a guess based on the dealer's comments, but it seems to make sense, at least to me!  And in just the same way that a stamp printed in fugitive ink will have its design dissolve and disappear when soaked in water, the postmark or precancel would remain.  Does that make sense?  What do you think?

Stamps aren't the only things that discolor -- I recently acquired this cover in a small lot of covers containing military-themed stamps and cachets.

Enclosed in the cover was a stiffener (shown below) that caused the discoloration.

If you have covers with stiffeners in them that aren't acid-free, I strongly recommend that you remove them.

Hi, Vince (stanley64):

Please see previous post in this thread, which is a quote of one of yours from the Canada 1898 Map Stamp thread.  I didn't want to clutter that fine thread with a tangential discussion about colour changelings.

Please accept my apologies for being so slow off the mark on your post from 13th Dec.  I missed it at the time, and only just happened upon it recently.  I am very interested to learn more about this other process (i.e. not sulphuretting) that results in colour changes that you mentioned to René (renden) in that post.

When I tried to access the link you provided, I couldn't get it to work.  So, before I start asking questions, I thought I would ask if you are able to restore or repair the link to the reference?  I would like to read that first to try to better understand what you have described as "oxidation; like rust".

Can you help?  Many thanks!

Thanks for posting Steve(tomiseksj ); the link does not show all the content referenced but at least it gives individuals reading the thread an idea of what is being discussed, i.e. sulphuration vs. oxidation.
Fortunately, my notes are more complete and I have shared them with Chris (Beryllium Guy ).


Happy collecting!