Help My Stamps Are Curling Why?

I'm on a little trip and I brought some loose stamps to sort and when I took them out and spread them out on the table I noticed that they are starting to curl why is this? ok I live in Sacramento area and we came up north to Lake Tahoe where the air is thinner and altitude is higher could this be why?

Moisture most likely

The humidity is the culprit very probably. Hopefully they will flatten out when back in dryer air.

Yes, it might be that there is less atmospheric pressure at that elevation to put weight on them to keep them flat. I suppose that on the moon they would just curl up into little tubes.

It might have to do with dryer conditions. Seems in high humidity they would lay flat and limp, then curl up as the moisture was removed. I'm assuming the stamps have gum on them, whether mint or CTO, and it just tightens up as it dries in relationship to the paper

Geeze, by the time I write my response, there are two others saying the exact opposite!

Japan & Indonesia maybe!

trust me Tahoe is much more humid than Sacramento

in my experience ,the dry air is the culprit.
in the winter I have a humidifier to counteract the furnace air temp.
however to much dampness is also a problem also.
the Answer is a happy medium.
David(DJD)

tina, I just had this happen to a mint stamp recently. It is now flat again. What most likely happens is fairly simple. The gum side (glossy gum at least) actually seals the paper fibers from moisture, so the moisture is absorbed from the face side of the stamp. The moisture, be it ever so slight, causes the paper fibers to swell. The gum does not and so the face side actually becomes slightly larger than the gum side. The result is a curling effect. The stamps should flatten as some have already stated when returned to a drier climate.

A trick in humid conditions to keep stamps dry is to place them in a small enclosed area such as a closet, with a 25 watt incandescent bulb lit at all times, but not too close to the stamps. The heat from the bulb helps keep the moisture level at a low. If you try this, experiment with the distance between stamps and bulb. Too close, could actually "toast" the stamps. I'd suggest 2-3 feet to begin with.

Marty

As others have said, there can be several factors - humidity being one of the biggest. Sometimes it is also caused by the type of paper used in an issue. Soaking modern German stamps is usually a challenge for that very reason. I have to soak then dry them under a lot of pressure (stack of books) for quite a while and some still come out curled.

I had not thought about dry air as a cause, nor have I had this experience. I wonder if the effect could possibly be similar but with the stamp curling in the opposite direct direction than one in a moist environment. Or could it be that different types of paper might also be a culprit? David, which way do your stamps curl? Gum side or face side on the outside of the curl?
Marty

Well, it appears we all have had a variety of experiences. Are you thoroughly confused now , Tina?

Oh for the lower humidities of the west. I live in the southeast (Georgia) and believe me I try not to collect mint stamps for exactly the reason that in our high humidities, it is just too much trouble to try to protect a mint stamp. I have had far too many bad experiences with stamps being ruined by high humidity.

Oh, in case I am not clear, I think it is the humidity.

oooo you bet ya im confused if im understanding correctly,its quite humid up here then.I know the perfect place to collect stamps mint,used,cto ect the place is Roseville,California,USA cause at my house i've never once run into this problem.If I do re-call correctly when we went to Reno,Nevada here a couple months ago I think my stamps slightly started to curl,but I thought it was just me thinking that

Hi Tina, don't fret too much. Most mint stamps have a natural curl, particularly earlier issues. It's commonly caused by the gum contracting after it dries - so it's usual to see stamps curl with the gum on the inside of the curl. It can also be caused by the weave of the paper fibers. Stamps of the same issue should curl the same way, as the paper is the same and the gum is applied the same. I collect only early issue mint stamps, and I hardly have a flat stamp. I prefer to photograph my stamps out of any mount or album to avoid specks of dust & light reflection etc, but often I can't as they just curl too much to photograph. (You can see an example in the Horse thread in the Topicals, last page where I posted a horse stamp, you can see the curl, although it's not great.)

It's actually one method of checking for alteration to a stamp's gum, checking it against another of the same issue to see if they curl the same way. Regummed or redistributed gum will alter the natural curl the stamp had.

This is not to say that humidity and/or heat will not accentuate curl, or cause a flatish stamp to curl, and they certainly aren't good for mint stamps as pointed out. But don't panic when you see a curled stamp, it's perfectly common.

Balf

Hi Tina.....

So, you live in Roseville..... nice community. For many years I use to live in Citrus Heights. Six years ago circumstances caused me to move away...... if I ever had the chance I'd move back. Did a lot of fishing at Folsom lake and both the rivers there.


Butch