Storing Your Comics
Some collectors have a lot of angst about storing their comics. The Library of Congress uses it, and they know a thing or two about preserving paper products. That said, mylar is more expensive and is not absolutely necessary for what I consider of the mill comics.
Mylar: A biaxially extruded polyester film that is simultaneously stretched in two directions to give it maximum strength. Resistance to diffusion of gases like oxygen, carbon dioxide, sulfur dioxide, etc. is 350 times greater than polyethylene. Resistance to moisture, insect attack, fungus, mold, mildew, acid, oils, grease, and solvents is excellent. Mylar is the Cadillac of storage bags.
Polyethylene: A polymerized ethylene resin that is inert, translucent and creates a lower static charge than polypropylene. The translucent nature of polyethylene prohibits a greater amount of light penetration than the transparent polypropylene. The lower static charge produced by polyethylene as opposed to the higher charge emitted by polypropylene means that polyethylene will attract much less dirt, dust and other foreign, organic elements. Polyethylene is more flexible than polypropylene.
Polypropylene: Propylene (CH3CH:CH2) is a sub stratum of ethylene. Polypropylene is a thermoplastic resin that is a polymer of propylene and is more rigid than polyethylene. Due to its rigidity, polypropylene sleeves are more prone to tearing, especially at the seams.
So, what do you need to use? If you have a very valuable comic (worth $30 $50 or more), I suggest using Mylar. For regular comics, I recommend polyethylene.
Here is what E. Gerber has to say about storing comics on their web site (keeping in mind that they are, after all, in the business of selling mylar bags):
Poly bags will not destroy your comics. We do not preach fire and brimstone.
They then swiftly move on to saying:
Poly bags will not actually destroy your comics. They will simply afford a lot less protection against the elements. I would definitely put my Sale comics into poly bags, but only for a short term, say a couple of months.
This is seriously implying that poly bags are not to be used for anything other than REALLY transitory storage. This is nonsense. That said, I likely be on board with this philosophy if my business was made up of selling Mylar bags to comics fans who are fearful that putting comics in poly bags is tantamount to wrapping them in a tissue and setting them out in the rain.
Generally, thicker bags are better. When buying mylar, you typically can go from 1 mil thick (called Mylites at E. Gerber and Arklites at Bill Cole) to 1.4 mil thick Mylite+ bags (from E. Gerber) to 2 mil thick (Mylite2 from E. Gerber, Arklites 2 from Bill Cole) or 4 mil thick (Mylite4 or Archives from E. Gerber and Comic Gards or Time Loks from Bill Cole). Personally, I dislike the 1 mil Mylites/Arklites (I bought the 1 mil Arklites). While the 1 mil thickness is the cheapest Mylar solution, they are very thin and feeling, though they should provide the same chemical protection as thicker Mylar. Moving up a step, I know people who swear by the 2 mil Mylite2/Arklites2 bags. Personally, nowadays if I going to take the step up to Mylar from poly bags, I go all the way to the 4 mil thick archival bags. In addition to the Mylar brand name, Bags Unlimited has Grade Archival Polyester in 2 and 4 mil thickness that is compared to Mylar and is a bit cheaper. I have never personally used or seen these bags and cannot speak to their quality.
Poly bags also come in a variety of thicknesses, with polypropylene typically being thinner (1.2 to 1.5 mil). The difference in cost between 2 mil polyethylene and thinner polypropylene is a penny or 2 per bag. Given the published differences between the 2 types of bags, I think 2 mil polyethylene is the bet for general comics storage (even though you can get polyethylene in 3 and 4 mil thickness, if I feel the need to go up to 4 mil, I am going to go to Mylar). A good place to get poly bags is Bags Unlimited.
Even the 1 mil thick Mylar bags cost 2 3 times as much as poly bags (wholesale/bulk). 2 mil Mylar bags can run anywhere from 18 to 22 cents each in bulk (PLUS shipping) and that does not include the board. For my collectible stuff I don mind spending 60 cents or so on an archival bag/board for a comic worth $30+, at least there the storage cost is 2% or less of the value of the item being stored.
Be careful, not all bags are made alike. There are various widths, make sure you buy the right width for the comics you need to store:
7 (aka Current) I do not like using this width. Frequently I find that a thicker annual or giant size comic just won fit, or even some indie comics that have slightly wider trims.
7 1/4 (sometimes called Standard, sometimes Bronze) A good overall width for most comics from the 1980s onward.
7 3/8 (This is Bill Cole width) Fits most comics from mid to late 1960s onward.
7 3/4 to 7 5/8 (Silver/Gold) Good for 1950s onward.
8 to 8 1/4 (Super Golden) Used for comics from the 1940s to early 1950s.
Are you someplace with high humidity? Do you have iss timberlands ues with mold, mildew and fungus in general? What about insects (especially the kinds that like to chow down on paper products, termites, silverfish, etc.)? Do you have a lot of these factors in your area and if so, do you take steps to manage them? There are things that can be done to manage your environment far before you get to the bags you keep your comics in, but the last line of defense if going to be the comic bag. For instance, I live in Southern California and we don have many bugs compared to someplace like Florida (well, most places don have a lot of bugs compared to Florida, but you get the idea). Even so, we are not totally bug free, and I have a service that comes out monthly and sprays the perimeter of the house and property line to keep bugs out. I rarely ever see bugs. Problem (mostly) solved. If you live in high humidity area, you might consider using some de humidification and anti dessicant solutions in the area where you store your comics.
These are rigid plastic sleeves that you slide a bagged/boarded comic into for additional protection. These are made of PVC and are not archival (like Mylar). I don see the usefulness of these for general comics in your collection. People usually bag and board a comic and put it in a box, they not tossing it around where they need this kind of extra protection. They could be useful if you shipping a comic in the mail and want the extra protection. BCW sells some of these with little stands built in that are kind of cool as a cheap alternative to a frame if you want a quick display for some of your comics.
Get what feels right for you, taking the knowle timberlands dge presented here into account. I like to take the value of a comic into account when determining the cost of the storage materials I use with it. You are not committing a against comics in using polyethylene bags. I have bought a number of back issues in old bags that are very yellowed and deteriorated (and have replaced those with new polyethylene bags). I believe those are mostly comics that have been stored in harsher environmental conditions than I have.
I personally have comics that have been in poly bags in my collection since the late 1980s (when I did a large scale re bagging effort, apparently not even using backing boards at that point in time). Above is a picture of a couple of comics in poly bags (I believe polypropylene) that have been in a comic box in my garage (stored upright in a low humidity environment) since late 1989. I see no particular degradation of the bags other than a bit of the comics inside are not degraded or damaged in any way. I believe that replacing poly timberlands bags ever 2 5 years is not necessary, but is encouraged by those that have a vested interest in selling collectors bags or up selling collectors on Mylar.
Everything else 2 mil Polyethylene bags
An aside on taping your bags: Some people like to tuck the flap in and don use tape, fearing that it will snag a comic when taking it in/out of the bag. I use tape, I like keeping that flap securely in place. If I am going to remove a comic from the bag I remove the tape COMPLETELY from the bag, I do not leave it hanging onto the flap where the possibility exists that it could snag on your comic.
A brief note on slabbing: The ultimate in protecting a comic is, of course, to get it by Comics G timberlands uaranty, LLC. The comic has MicroChamber paper inserted inside the front and back covers, is sealed in Mylar, and then encapsulated in a hard plastic shell (also called a The downside that the slab cannot be opened without breaking it and you never be able to open and read your comic again unless you want to the slab and then you need to pay a lot of money to have the comic be re graded re slabbed if you want it back in the slab. Compare this to using archival Mylar where you take off the tape, place it safely to the side, remove your comic from the sleeve, read it, and then return it to the sleeve and re tape it.