Or in other words, comic book sleeves, come in many types. They have bags made out of polyethylene, polypropylene, and Mylar (polyester). The main usage is to protect your collection from dust, dirt, finger oils and other airborne pollutants.
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.
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.
Via Comics Spectrum Blog
Comic Backing Boards
Comic book backing boards are used to prevent your comics form being bent or folded. It is a piece of cardboard that is designed to keep comic books flat and upright during storage. There are several types of boards from the normal chipboard to the ‘super’ acid-free board. The standard size will fit comfortably into any current size comic bag.
Which Type of Comic Book Bags and Boards am I Using?
When it comes to bags and boards, there’s been a lot of controversy and discussions on that topic. Obviously, mylar is the one to go. Mylar will last longer than you will 🙂
Mylar last significantly longer, with claims that you will not have to change the bag for 150 years!
However, mylar comic bags are expensive.
If you have a small collection, I think it is still OK, but if you have thousands of comic books in your collection, putting all of them in Mylar comic sleeves will be expensive. You may end up not able to afford to collect comics anymore.
I am using the cheaper version, the regular poly bags. People are saying that if you are using this type of sleeves, you need to change them regularly, maybe after 3 years.
Naah! These people are bluffing.
Marketing reason maybe?
The last time I changed mine was 8 years ago and my comics are still in fine condition. The reason I made the change was due to the sleeves got torn easily especially at the seams. I think it was the Polypropylene bag type. As per the statement above – 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.
However, you need to always make sure you do this:
- Keep your comics away from moisture
- Keep your comics away from any heat source
- Don’t keep them in attic or basement where the extreme temperatures either hot or cold change drastically. Make sure your attic or basement is correctly insulated if you have no choice.
How to board and bag your comics?
The first thing you need to do is to take the backing board and insert it into the comic bag. After that, put your comic inside the bag as the pictures shown below.
And you are done.
Whatever your preferences, check them here: