You don’t have to have superhuman strength or x-ray vision to appreciate comic books and to yearn to collect and preserve the graphic stories of childhood and beyond. But there are some simple steps every fan should take to store a comic book collection—to ensure it retains its value and can be enjoyed by the next generation.

Whether obsessed with everything Wonder Woman for years or inspired more recently by movies to start collecting Iron Man, our tips from comic-store owners will help you preserve your assets. After all, some comics sell for thousands or even millions of dollars. Our experts share products and practices they’ve used to keep their comics pristine.

“With comic books, you want to make sure they are bagged and boarded,” said Michael Freedman, owner of Comic Smash. Bags that protect comics come in different types of clear plastic including polyethylene, polypropylene and mylar.

The type you choose may come down to preference and how much you are willing to spend.

“I keep all of my books in polypropylene but some people swear by mylar. However, my experience with mylar is that it starts to yellow and has to be replaced every five or so years,” Michael said.

Comic Book Storage Types

Comic Book Bags

Bag sizes depend on what year your comic book was published:

Current – 1980’s to today, size 6 7/8″ x 10 1/2″

Silver Age  – 1950’s to 1980’s, size 7 1/8″ x 10 1/2″

Golden Age  – pre 1950, size 7 3/4″; x 10 1/2″

Again, this also may be a matter of preference, but Michael says he uses Silver Age for all his books, with the exception of Golden Age, which requires a larger format, but some collectors like the tighter fit of Current size so they will buy specific bag sizes.

Cat Jercan, owner of DJ’s Universal Comics, believes too much thought goes into the different types of plastics and sizes.

“Don’t spend a lot of money on it. Damage only occurs if the books are exposed to light and air. If you keep them bagged and boarded in whatever bags you like and store them in a box, they’ll be fine.”

Comic Book Boards

Cardboard “boards” are used as backing in bags to keep comics crease-free. Look for acid-free to avoid damaging the pages of your comic books. If you purchase a comic already in a bag with a board, consider asking the dealer if he uses acid free boards.

“The store owner may have gone with a cheaper board to save money and there isn’t anything on the board that will tell you if it’s acid free,” said Michael who recommended you ask to see the packaging the boards came in or get the name of the board brand.

Hardshell Cases for Comics

For special comic books, many collectors opt for hard plastic holders. It costs a bit more than a bag and board, but prevents the book from damage or creasing if it is dropped and keeps the pages from bending. It can also be propped up for display like a picture frame.

Comic Book Grading and Slabbing

If you have vintage and rare comic books or plan to sell them, it may be worth spending a few dollars to get them graded through a company called Certified Guaranty Company (CGC). “The grade locks in the value,” said Michael. Then they seal the book into a hard plastic clam case called a ‘slab’ and put a hologram sticker on it and a barcode.” If that sticker is torn or the case opened, the grade becomes invalidated.

“I tell people to spend the money to do this, especially if they plan to try to sell the book on eBay,” says Michael. “I’ve heard a lot of horror stories of sellers shipping original vintage books off to be sold, then the buyer says they don’t want it and sends back a cheap reprint and there’s no way to prove that they took the original – unless you had it graded. And don’t forget to buy insurance on the shipping!”

Comic Storage Boxes

Most collectors store their comic books in cardboard collector’s boxes that come in two size – long and short. These boxes are made so comic books can be placed standing upright. If you’re willing to spend extra money, there are also soft plastic boxes, which are more durable and that Cat credits with saving much of his inventory when a plumbing issue led to a flood in his store.

When storing boxes, Michael cautions not to stack them too high. “The weight will start to break down the boxes on the bottom and your comic books could get crushed. I usually don’t go any higher than five boxes.”

Control the Storage Environment

As with most collectibles, the environment you store in is important. Bagging your comic book can do a lot to keep out moisture and paper-loving pests such as silverfish and bookworms. But is temperature important? We found conflicting opinions:

“Paper expands and contracts with hot and cold,” said Michael. “So you don’t want to store them anywhere that has extreme temperatures, like in your garage if you live in a place like Chicago.”

To the contrary, Cat didn’t feel temperature control was important. “I had my collection in a storage space in a city that would get hot as an oven. They were all bagged and boarded and in a storage box. I never took them out and after being stored for 10 years like that, they were fine.”

Comic Book Storage Don’ts

Michael also had a list of don’ts he’s collected over the years.

DON’T stack them. The pressure from the top books will damage the ones at the bottom of the pile. Bag and board them, and stand them upright in a storage box or file cabinet.

DON’T store cardboard boxes on the floor of your garage or basement. Put the boxes up on milk crates or wooden pallets because a flood or water leak will destroy your books, even if they are bagged.

DON’T put all of your comic books out on the patio, even just for the night, while you’re cleaning out your basement or wherever. That WILL be the night it rains.

DON’T leave your comic books around dogs or children.

DON’T eat or drink while reading your collectible comic books.

DON’T smoke around books that are out of their bags. It will yellow the pages.

DON’T roll them up and put them in your back pocket like kids did in the ‘50s. It will crease the pages.

While comic collecting can be an exciting hobby, Michael cautions that it’s rare that you can make a lot of money from collecting and selling current comic books. Caring for you comic books is mainly about keeping your beloved favorites in good condition so you can enjoy them and perhaps pass them down to children in the family. But for those who get their hands on early vintage books or those with characters that get a movie made about them, they can go up significantly in value.

So it’s worth it to keep your collection in good shape with a little know-how and a few supplies.

And don’t forget, you can add to your collection every year on Free Comic Book Day! Look for it at participating comic book stores this year on Saturday, May 2.