Storing a CGC Comic Book In A Vacuum Sealed Bag?

[valiantman]

tubs which have a nipple

 

Uhhhh... huh huh.

You said 'tubs'.

 

[fantastic_four]

Oh my GAWD, the answer the Library of Congress sent me was INCREDIBLY detailed and useful! Here's the summary of it--vacuum sealing is harmful, and dessicants don't work well because you have to constantly change them. Here's the full text of the response:

 

 

Dear James Ashley Rudd,

 

Thank you for your questions concerning preservation. Contrary to popular belief, neither polyester film, nor polyethylene or any other plastic film is in itself conducive to the longevity of paper - except from a short-term perspective. The benefit from "encapsualtion" between two sheets of a clear plastic film, derives largely from the protection that this practice provides from potential injury to the object from physical handling. Encapsulation may also protect objects from water damage in the unlikely event of a water sprinkler going off in a fire situation.

 

Our most current understanding of the aging of paper is that it loses strength and suppleness and ultimately becomes brittle due mainly to acid hydrolyitc degradation caused by formic and acetic acids that are produced constantly within it. These acids continue to accumulate making the paper increasingly vulnerable to the aging process. The adverse effect of these acids can be reduced by

 

1. lowering the temperature and the relative humidity under which it is stored so as to minimize the dissociation of these acids (these acids are harmless in their undissociated state),

2. by sandwiching the object between two sheets of paper or board with a high alkaline reserve so that these acids would be absorbed and neutralized by the alkaline paper or board, and

3. by a chemical treatment that will not only neutralize the acids, but also provide an alkaline reserve that would continue to protect against acids that will form in the future.

 

Encapsulation by itself can be actually harmful because it does not let the acids formed within paper diffuse away, but instead enhances their accumulation. In laboratory experiments carried out under elevated temperature and relative humidity conditions, under which these acids should diffuse more easily, even test papers placed inside L-sealed polyester envelopes (sealed along only two of the four edges) tended to age at a rate comparable to that obsrved for test papers aged within fully sealed envelopes. On the other hand, a backing of an alkaline matboard within a polyester film envelope or capsule, or inside a picture frame, has been shown to provide a more beneficial environment. The difference in the latter approach is that the alkaline backing can act as a sponge to soak up acids.

 

However, for the most brittle paper objects which may be too delicate to handle, encapsulation does provide much needed support and reinforcement to enable their handling while preventing physical damage. That is the only circumstance in which I would encourage encapsulation. Even in such a case, it would be preferable to support the object first an alkaline paper or board. Unfortunately, this last option may not be available for manuscripts or other objects that need to be viewed from both sides.

 

One effective and functional approach to store a manuscript for the long term may be to interleave the individual sheets comprising the mauscript with alkaline paper and insert this package within an alkaline folder. A photocopied facsimile of the manuscript can be placed within a clear polysester jacket attached outside the folder to show what is inside. Whenever it becomes necessary to handle the manuscript, the photocopy can be pulled out of this jacket and manipulated rather than the original.

 

In terms of using dessicants, we do not recommend them for long term use or storage, mainly because they would have to be constantly changed, once they have absorbed the moisture and treated to remove the moisture before they can be returned to the storage area to again become saturated with moisture and then again be treated to remove the moisture. They work great for short term solutions such as exhbition cases, etc. I would recommend the use of a dehumidifier in the room where the objects will be stored. Even a small dehumidifier will in the long term cost less then the amount of dessicants needed to maintain good environmental conditions.

 

Thank you for your interest in preservation.

[drbanner]

Good stuff JR...thanks.

 

Sounds like even having books in a mylar provides a "micro-environment" trapping the organic acids, but I suspect that buffered boards do a nice job of neutralizing those for a good, long while. The question now becomes what is the buffering capacity of the micro-chamber paper???

[fantastic_four]

The question now becomes what is the buffering capacity of the micro-chamber paper???

 

And of E. Gerber/Bill Cole calcium carbonate-buffered boards.

[lighthouse]

Wow... a return on our tax dollars... kind of scary...

 

Paper is its own worst enemy ... at least it has been since the late 1800's... There is a section on the LOC website that describes how paper made before 1880 lasts many times longer than papers made today, because of the use of cotton fibers instead of wood pulp. Acid migration in the cotton is so low that it can take hundred years for the paper to break down in conditions that would destroy newsprint in 10...

 

Thanks for posting this FF... although you may find yourself reposting it about once a month from now until the end of time.

[lighthouse]

The question now becomes what is the buffering capacity of the micro-chamber paper???

 

And of E. Gerber/Bill Cole calcium carbonate-buffered boards.

 

I had been previously been told that Fullbacks should be changed every ten years, to maintain their ability to absorb the migratory acids. But I am sure it depends on the book. A newsprint book will degrade faster than a Baxter paper book. And even among the newsprint books, there are different qualities of newsprint. We've all seen differences between the publishers...

 

One thing to consider. Placing a Fullback behind a comic is only effective if the paper in the cover is the same as the paper in the interior. On older books, this is nearly always the case. But on books where they are fundamentally different materials, the cover may prevent the acid from the interior pages from reaching the fullback. An example is Ultimate Spider-Man 1... The cardstock cover acts as a semi-permeable barrier, and a fullback behind the book is less able to do its job. Acids from the interiors pages transfer between each other smoothly, but cannot transfer through the cover at the same rate...

[fantastic_four]

I had been previously been told that Fullbacks should be changed every ten years

 

Do you remember who told you that?

[lighthouse]

I had been previously been told that Fullbacks should be changed every ten years

 

Do you remember who told you that?

 

Man, that's four typos already this morning. I must be more tired than I thought...

 

I honestly don't. But I remember I had no inclination to doubt them, and I am notoriously skeptical... So it was probably someone who knew what they were talking about...

 

Unless it was a girl I was trying to hook up with at the time...

[OldGuy]

Isn't what they said in that letter basicly what is on their web site here?

[BachelorOfComix]

here?

[OldGuy]

I fixed it for those to stupid to cut an paste.

[Arty]

Are you sure that's true, that gaseous water (humidity) can't pass through Melinex?

 

First I have to admit my assumption that mylar is both water and vapor proof is wrong.

 

"Mylar polyester film is virtually impermeable to the liquid phase of most chemicals and reagents." Link to mylar properties pdf

 

but vapor can transmiss trough it.

 

 

 

FF: How can you say for sure vacuum sealing is harmful? reply you got doesn't mention it at all? (only encapsulation/sealing)

 

Encapsulation isn't harmful if done properly-with alkaline buffer/microchamber paper (otherwise CGC would be in deep trouble since their business is encapsulating valuable paper collectibles)

 

From link Oldguy provided:

Aging of Paper Sealed within Polyester Film

 

 

Notes:

Sealed=Sheets encapsulated inside sheets of 4-mil thick polyethylene terephthalate (PET) film by sealing off all four edges completely,

 

Half sealed=sheets sealed inside half-open PET envelopes, sealed along two adjacent edges,

 

Permalife=sheets encapsulated along with an alkaline paper,

 

Deacidified=sheets deacidified with aqueous magnesium bicarbonate and then encapsulated by sealing along all four edges, and

 

Control=control sheets which were not treated in any way or encapsulated.

 

 

Most interesting things about this graph:

1 half sealed in mylar=as bad as completely sealed.

2. It seems that using alkaline buffered materials (backing boards etc.) is much more important than using mylar.

 

Finally I disagree slightly about use of dessicants (silica gel).

First: it isn't that expensive 16$/kg (1kg is needed for one cubic meter- that's a LOT of comic boxes)

Second: it could be reused infinitely (onse saturated with water they can be reconditioned by heating in oven.

 

Of course they are impractical for dehumidifying entire rooms.

 

 

[fantastic_four]

FF: How can you say for sure vacuum sealing is harmful? reply you got doesn't mention it at all? (only encapsulation/sealing)

 

What's the difference? I asked the LoC specifically about "vacuum sealing" and they equated it with encapsulation and sealing in their response. In all of those situations the book is left to stew in its own juices.

 

 

Encapsulation isn't harmful if done properly-with alkaline buffer/microchamber paper (otherwise CGC would be in deep trouble since their business is encapsulating valuable paper collectibles)

 

How do you know they aren't in trouble? Everyone is still wondering whether they're supposed to change that microchamber paper every 7 to 10 years.

 

 

Most interesting things about this graph:

1 half sealed in mylar=as bad as completely sealed.

2. It seems that using alkaline buffered materials (backing boards etc.) is much more important than using mylar.

 

Half-sealing being as bad as completely sealed is definitely interesting...the implications of that are far-reaching enough to where I'll be contemplating it for a while before I comment much about it! And yep, melinex doesn't help, it just doesn't hurt like polyethylene/polypropylene do by becoming acidic after 5 years or so. There are a few things I can't tell about the graph:

 

• In the "permalife" testing, they say the sheet was encapsulated but don't mention sealing. Does this mean it was open on all four sides?
• What does the "fold" being charted on the y-axis mean? What are they folding, and how?

 

Finally I disagree slightly about use of dessicants (silica gel).

First: it isn't that expensive 16$/kg (1kg is needed for one cubic meter- that's a LOT of comic boxes)

Second: it could be reused infinitely (onse saturated with water they can be reconditioned by heating in oven.

 

Of course they are impractical for dehumidifying entire rooms.

 

How do you know when they're full, and how long do they last before getting full?

[fantastic_four]

Isn't what they said in that letter basicly what is on their web site here?

 

Maybe...lot of techno talk and weakly summarized information there that'll take a while to sort through, but definitely an interesting link!

[Arty]

 

Quote:

--------------------------------------------------------------------------------

FF: How can you say for sure vacuum sealing is harmful? reply you got doesn't mention it at all? (only encapsulation/sealing)

--------------------------------------------------------------------------------

 

What's the difference? I asked the LoC specifically about "vacuum sealing" and they equated it with encapsulation and sealing in their response. In all of those situations the book is left to stew in its own juices.

 

There is a big difference: presence of air. (Oxygen increases decay and aging.)

As hobgoblin said earlier in this thread:"in one sense sealing in a vacuum slows the aging but would trap the gases."

It might be more harmful than normal sealing though, as suggested by lighthouse

 

Quote:

--------------------------------------------------------------------------------

Encapsulation isn't harmful if done properly-with alkaline buffer/microchamber paper (otherwise CGC would be in deep trouble since their business is encapsulating valuable paper collectibles)

--------------------------------------------------------------------------------

 

How do you know they aren't in trouble? Everyone is still wondering whether they're supposed to change that microchamber paper every 7 to 10 years.

 

well I just hope they aren't

 

Quote:

--------------------------------------------------------------------------------

Most interesting things about this graph:

1 half sealed in mylar=as bad as completely sealed.

2. It seems that using alkaline buffered materials (backing boards etc.) is much more important than using mylar.

--------------------------------------------------------------------------------

Half-sealing being as bad as completely sealed is definitely interesting...the implications of that are far-reaching enough to where I'll be contemplating it for a while before I comment much about it! And yep, melinex doesn't help, it just doesn't hurt like polyethylene/polypropylene do by becoming acidic after 5 years or so. There are a few things I can't tell about the graph:

 

 

In the "permalife" testing, they say the sheet was encapsulated but don't mention sealing. Does this mean it was open on all four sides?

What does the "fold" being charted on the y-axis mean? What are they folding, and how?

 

I believe encapsulation means sealed on all four sides. (Well at least on two sides. How it could be even possible to "encapsulate" anything with all four sides open?)

 

As far as I can understand: They create a fold (crease) in paper and then again fold it backwards (creasing it over an over again in the same place)

Number in Y-axis means how many times paper is folded until it breaks.As seen in chart, in some cases paper is so brittle only one fold is needed.

 

Quote:

--------------------------------------------------------------------------------

Finally I disagree slightly about use of dessicants (silica gel).

First: it isn't that expensive 16$/kg (1kg is needed for one cubic meter- that's a LOT of comic boxes)

Second: it could be reused infinitely (onse saturated with water they can be reconditioned by heating in oven.

 

Of course they are impractical for dehumidifying entire rooms.

--------------------------------------------------------------------------------

How do you know when they're full, and how long do they last before getting full?

 

Some types of colored silica gel change color when saturated with water. (This colored silica gel is added to normal silica as indicator) See link

more environmental monitoring products (silica gel etc,)

 

It's impossible to tell how long they last (depends on what kind of conditions they are used naturally)

 

Note: My english is far from perfect so sometimes I might have misunderstood some minute differences in some terms (I often use sealing as synonym for encapsulation etc.)

[fantastic_four]

There is a big difference: presence of air. (Oxygen increases decay and aging.)

As hobgoblin said earlier in this thread:"in one sense sealing in a vacuum slows the aging but would trap the gases."

It might be more harmful than normal sealing though, as suggested by lighthouse

 

I can't tell whether this is an argument for or against vacuum sealing. My main problem with it still is that the pros with all this research in hand don't do it, although I'm still interested in the specifics.

 

 

I believe encapsulation means sealed on all four sides. (Well at least on two sides. How it could be even possible to "encapsulate" anything with all four sides open?)

 

Like you said, they used the term encapsulation with four sides sealed, two sides sealed, and they failed to use the word encapsulation with no PET used at all. Since they were specific everywhere else, I took it to mean they put it between two sheets of PET with no sides sealed, but it's quite unclear. I'm having trouble putting this one into perspective since they've got pictures on their web site of envelopes they use with sealed sides...the graph seems to indicate that bags without massive ventilation are harmful.

 

 

It's impossible to tell how long they last (depends on what kind of conditions they are used naturally)

 

Ballpark is good enough. Assuming a given relative humidity ranging between 50% and 60%, is it hours? Days? Weeks? Months? Years? I don't see how you can use them without this type of information.

[stagedoorjohnny]

 

Your graph on the Springhill offset's aging in various forms of storage may be irrelevant. I believe Springhill offset is a groundwood free type of paper made by International Paper and is also chemically bleached for whiteness during the paper making process. Comic books are all groundwood grade like newsprint which makes them much more sensitive to the aging processes. Comparing groundwood free sheets to groundwood paper is like comparing an apple to an orange if this is in fact the case.

 

Stagedoorjohnny

[garthgantu]

Some points to consider:

- As FF noted, CGC may well not even know about this information, though you would hope they'd be well aware of it. But remember, the LoC is focused on preserving documents - many/most of them paper-based - for centuries, not years or even decades. So their advice is presumably based from this perspective. That said, there would appear to be every possibility that encapsulating ("slabbing") a comic book is not advisable for long-term preservation.

 

- It may be that CGC did some further research and determined that re-slabbing every 7 years will in fact more or less ensure the preservation of an encapsulated book, by releasing the acid-saturated air within, and by allowing for the replacement of the acid-absorbing board. *If this is the case, CGC should really be telling people to re-slab in much stronger terms...but of course, you don't want to scare off customers by convincing them that they're getting themselves into a 7-year cycle of shipping, insuring, re-slabbing, paying, paying, paying...

 

- to Arty's point about condensation, I would respectfully submit that unless we're talking about the windscreen of the Space Shuttle, almost no transparent materials are truly capable of keeping water out, regardless of how carefully those materials are sealed... condensation can accumulate in just about any sealed container, given the proper conditions.

 

- Something tells me the build-up of the formic acid referenced in the LoC response has to be particularly egregious in the TTA and Avengers issues featuring Ant-Man...

[fantastic_four]

- It may be that CGC did some further research and determined that re-slabbing every 7 years will in fact more or less ensure the preservation of an encapsulated book, by releasing the acid-saturated air within, and by allowing for the replacement of the acid-absorbing board. *If this is the case, CGC should really be telling people to re-slab in much stronger terms...but of course, you don't want to scare off customers by convincing them that they're getting themselves into a 7-year cycle of shipping, insuring, re-slabbing, paying, paying, paying...

 

This is what I see to be the most likely snapshot of their thinking... the fact that they put the microchamber paper in there to begin with indicates they must've known about the buildup of acid.

[garthgantu]

Don't you think they should be more forthright about the fact that your slabbed books are in danger of aging *faster* inside the slab if you don't re-slab every 7 years or so?

 

Do you think CGC will be sending mail/email "reminders" to its customers as their respective "7-year anniversaries" roll around?