Yellowed Glassines Harmful?

Received a small order in a well used yellow glassine. Is that harmful to the stamps?

*** Moved by Staff to a more appropriate forum. ***

Opinion:
Yes it is, very much so sdtom,
Glassine is merely very hard pressed paper, it brings with it, paper foxing problems etc, if kept for a long time, (In the main, as with stamps, affected by the humidity of the collection location)

I have seen Mini sheets, mounted on a page, using the corner of Glassine bags as
corner mounts, these have survived well over 30 years.

Any sign of yellowing, discard.

If the vendor of stamps has sent you in yellowed glassine, I'd suggest all is well, providing you ditch the glassine envelope asap.

I already discarded and replaced it with a fresh savage glassine envelope. I found these film negative storage to be good.

In my opinion, dealer sending stamps in old yellow glassines is bad, mainly because of the implications for condition of other material that might be on offer or sloppiness in packaging/storage. It doesn't cost much to enclose stamps in a brand fresh spanking new glassine. Personally, I'd find a new dealer.

However, I have limited experience with yellowing of glassines, mainly limited to the old glassines from my childhood that were dug out when returning to the hobby as an adult. I expect/hope that glassine material has improved over time and is now acid free like most paper.

Has anybody used sheets made out of the plastic(?) bags used in boxes of breakfast cereal to separate stamps/panes/PBs?
They look like waxed paper; but, don't feel that there is wax involved.

I would give one of the companies a call and ask them what it is made of. I think there is plastic involved in the manufacture but I'd check to be sure.

For other waxed paper or plastic there are likely oils added to the product either directly or indirectly. I would not recommend it.
I agree that discolored/degraded glassine material should be immediately replaced.

Further research on 'always' reliable Google shows they're made of high-density polyethylene (HDPE).
I haven't found any posts shooting it down as damaging to stamps.....but, since everybody has an opinion, I'm sure somebody has one that will.
btw I've found the new Canadian $100 bank notes work well....but, I've quickly run out of them.
So, if anybody wants to help me with getting more, send them to me.

The danger of wax paper would be in long term storage because any pressure plus heat most likely would melt the wax to what ever it makes contact with front or back of the stamp .
I disagree about the more popular glassines from the 1940's and 1950's ,I never seen any sign of damaged to the stamps. Would add that some of the stock books from the 1990's that are coming out of South Asia and China are showing yellowing of the stamp paper due to the chemicals in the clear mounting strips on the stock pages .

Anyone buying from me will likely receive a yellowed glassine. Why? I bought several complete boxes of NOS (new old stock) glassines from the 1950s or 1960s, and I use them for shipping. Of course I do not generally put stamps directly in them. The stamps are in a 102 card that is then placed in the glassine.

Then again, I always assume that buyers (myself included) likely will remove stamps from any shipping glassines anyway.

I agree with floortrader though; I've not seen stamps damaged directly as a result of glassines. Tape glue affixed to the glassine, yes. Rust from ancient paper clips, yes. Disintigrating glassines, yes... but not the glassine in and of itself.

A couple of years ago I processed a large lot of unused US blocks of four put into glassine envelopes starting in the late 1930s. I was amazed at how fresh the stamps were, especially a block of US 260, the orange unwatermarked 50 cent stamp. Stamps stored in plastic approval cards seem to lose color and freshness over time. Sometimes it is possible to see the outline of stamps designs on the clear plastic after the stamps are removed from the card. I have also had good luck with Blue Ribbon mounts (now Hawid) from the 1960s. Paper approval cards or black paper sheets seem to be more of a problem especially if the cream color card or page has turned brown. My bottom line is that glassine is safer than plastic or paper for long term storage of stamps. It maybe that close proximity to plastic when ventilation is lacking will more rapidly degrade stamps than the looser confines of a glassine envelope.

Stamp Ink Migration, General Franco Spain issue.
Held in Hagner's "Vis O grip" card from Sweden.

The history of the stamp in the card is unknown.

To paraphrase Monty Python, all glassines are sacred. I keep most everything I get until they are torn.