Is it Safe to Store Collectables in Vinyl Pages or Holders?

BCW Vinyl ProductsCollectors of trading cards, comics, currency and other keepsakes want to store their valuables in a method ensuring their prized items will be safe for years to come. Toploading holders, vinyl coin flips and vinyl pages are a common solution, allowing hobbyists to organize an entire collection in an economical fashion.

At BCW Supplies, we often get asked if our vinyl products offer a safe storing method. To answer the question, let’s take a look at the basic science of vinyl. There are two types of polyvinyl chloride (aka PVC or vinyl). There is flexible vinyl, like the shower curtain that you likely have in your home, and there is rigid vinyl, like the clear, hard plastic that batteries are packaged in. Flexible vinyl has plasticizers in it that keep the vinyl pliable. That is what you smell when you take a vinyl shower curtain out of the package. Under certain conditions, such as excessive heat, the plasticizers from the flexible vinyl can migrate and damage ephemera. This is why we don’t recommend flexible vinyl products for long-term storage (they can, however, be used safely for short-term storage). Rigid vinyl, like the vinyl that we use in our toploaders, does not contain plasticizers and are inert. They will not damage the collectibles stored in them.

What’s Behind BCW Comic Book Backing Boards?

BCW Comic Book Backing BoardsIf your goal is to preserve your comics for years to come or if you want to keep your comics in mint condition as an investment, BCW offers several methods to protect, store and display comic books. While there are more elaborate methods of storing comics, let’s focus on the most common method – bagging and boarding. The combination of bags and boards is a trusted method by collectors of comics and is a cost effective way to protect an entire collection. BCW offers bags made of polypropylene and mylar, both are acid free, archival quality materials. Let’s narrow our discussion even further to backing boards. To keep your comic books in mint condition, you don’t want any old cardboard stored with your comics. BCW backing boards have special qualities that make them ideal for preserving comics.

First, BCW offers backing boards sized for Current, Silver Age and Golden Age comics. In each case, the boards are slightly larger than the comics to protect the comics’ edges, but the boards fit in the bags with the comic appropriately.

Second, our boards are cut from 24 point stock. This heavy board weight provides a firm backing which resists warping and protects your comics while handling and storing these floppy collectibles.

Third, BCW backing boards are acid free. They get their white appearance from a bleached sulfate process which does not interact with your comics. We have confirmed our boards are of archival quality by getting them tested by an independent lab, Chicago Paper Testing Laboratories of Northbrook, IL. They ran a number of tests on our boards, including a pH balance test (Acidity/Alkalinity, Hot Extraction Method, TAPPI T-435), an alkaline reserve test (ASTM D-4988, % of CaCO3), artificial aging test (Dry Heat Method, ASTM D-776) and a Fiber Analysis Test (TAPPI T-401 Using Graff “C” Strain). As you would expect from the scientists at Chicago Paper Testing, the results get technical, but BCW backing boards received good marks from the lab. If you want to see the technical results, learn more here.

Lastly, the backing boards help preserve the comics by absorbing the residual acid that migrates from the comics. Most comic books have been printed on newsprint. This includes all comics printed prior to Modern Age, as well as some Modern Age comic books. This newsprint paper has been bleached with acid prior to printing, and some of the acid remains in the paper. As time passes, this acid will degrade the newsprint, affecting the quality of the paper and the inks. BCW boards have been buffered with calcium carbonate which neutralizes the acid that migrates from the comic. The coated side may be on one or both sides of the backing board. You can identify the coated side by the glossy finish of the board. When you insert your comic and board inside the bag, you’ll want the coated side of the board facing the comic. If the board is coated on both sides, either side will work great. It is recommended to replace the backing boards in your comic collection every three to five years to rid the acids that have migrated from the comics into the boards.

Of course there are other important considerations for preserving your comics. You will want to store them away from sunlight and in a cool dry place because sunlight, heat, and moisture can directly damage the comics and accelerate the acid migration process, further damaging the comics. BCW offers several boxes and box dividers to help keep your comics safe and organized.

Learn more about BCW comic book products:
BCW Comic Book Backing Boards
BCW Comic Book Bags
BCW Comic Book Bag and Board Combo Packs
BCW Comic Book Boxes
BCW Comic Book Displays
BCW Comic Book Accessories

Are BCW Backing Boards Really “Acid Free”?

Comic book collectors are serious about keeping their comics in mint condition. Protecting their comics by bagging and boarding is common practice. So when BCW Supplies claims our backing boards are “acid free”, collectors say “prove it”. BCW welcomes the challenge.

Originally posted by BCW Supplies on a Collectors Society forum on June 9th, 2011, the article below shows the results of an independent test performed by the Chicago Paper Testing Laboratory. The “SBS” boards mentioned below are solid bleached sulphate, a virgin fiber grade of paperboard.


Once again we would like to thank mschmidt for his thought provoking study which you can find here; http://boards.collectors-society.com/ubbthreads.php?ubb=showflat&Number=4534727&fpart=1

Based on Mike’s data and conclusions we decided to have the products that are represented in his experiment tested at an independent laboratory. Mike had concluded “that [SBS] boards will actively contribute, on a molecular level, to the decay of your comic book from the moment they’re placed inside the bag” based on the results of his testing using a pHydrion pH pencil. Mike stated that the calcium carbonate coating of the SBS board was absorbing only the acid from the board itself and that over time the SBS board would become completely acidic. However, we at BCW stated that we believe Mike’s conclusion is in error. We suggested that the fact that the coated side of the BCW board became more acidic with use over a two year period indicates that some of the residual acid from the comic book is being absorbed by the calcium carbonate coating on the board. Further, we suggested that the fact that the uncoated side of the BCW board did not change in pH over a period of two years of use meant that acid was not migrating from the SBS board to the comic book. As you will see, the data below supports our position.

We submitted samples to Chicago Paper Testing Laboratories, Inc. on 20 July 2011 and I was present in the laboratory on Tuesday 2 August 2011 for some of the testing. We had the lab perform TAPPI T-435 (pH) on a comic book (Marvel Comics Presents #61), E. Gerber Half-Back, BCW Comic Backing Board, Bill Cole Thin X-Tender, Miller Hobby Comic Backing Board, and an Ultra Pro Comic Backing Board. We also had them perform ASTM D-4988 (Alkaline Reserve) on an E. Gerber Half-Back, BCW Comic Backing Board, Bill Cole Thin X-Tender, Miller Hobby Comic Backing Board, and an Ultra Pro Comic Backing Board. In addition, we had them perform TAPPI T-401 (Fiber Analysis) on an E. Gerber Half-Back, BCW Comic Backing Board, and Bill Cole Thin X-Tender. And finally, we had the laboratory perform ASTM D-776 (Artificial Ageing) on a comic book (Marvel Comics Presents #61) and backing boards from both E. Gerber and BCW for 10 and 20 years.

Let’s look at the results of TAPPI T-435 (pH) from the samples submitted;

Comic Book pH 5.4
E. Gerber Half-Back pH 8.52
BCW Comic Backing Board pH 8.47
Bill Cole Thin X-Tender pH 8.57
Miller Hobby Comic Backing Board pH 9.36
Ultra Pro Comic Backing Board pH 7.94

As you can see, the comic book is acidic as expected. The boards all have relatively the same pH with Miller Hobby at the top of the scale and Ultra Pro at the bottom.

Now let’s look at the results of ASTM D-4988 (Alkaline Reserve);

E. Gerber Half-Back 7.69%
BCW Comic Backing Board 3.64%
Bill Cole Thin X-Tender 6.57%
Miller Hobby Comic Backing Board 4.45%
Ultra Pro Comic Backing Board 4.72%

From the data we can see that the E. Gerber Half-Backs and Bill Cole Thin X-Tenders actually have more than twice the Alkaline Reserve as advertised. The SBS boards all have about the same Alkaline Reserve with Ultra Pro at the top of the scale and BCW Supplies on the bottom.

Let’s take a look at the results of ASTM D-776 (Artificial Ageing);

Aged 10 years

Comic Book pH 5.45
E Gerber Half-Back pH 8.07

Comic Book pH 5.44
BCW Comic Backing Board pH 7.62

Aged 20 years

Comic Book pH 5.27
E Gerber Half-Back pH 8.07

Comic Book pH 5.26
BCW Comic Backing Board pH 7.34

From the data we can see that the E. Gerber Half-Back’s pH level does not change over a 10 year period which suggests that the E. Gerber Half-Back does not absorb any residual acid from the comic book. This is the conclusion that we drew from Mike’s data originally, and it is also the position of E. Gerber that their product does not absorb any residual acid from a comic book. It only acts as a stiffener. As the BCW Comic Backing Board absorbs some of the phenolic acid that migrates from the pages of a comic book the pH level of the board naturally decreases as the buffer reaches the saturation point (which is why we recommend that you change your boards every 3 to 5 years). Phenolic acid is released as lignin breaks down in the pages of a comic book and exhibits itself as the yellow residue that you see on a comic backing board after several years of use.

Please note that ASTM D-776 does not allow for the micro-environment that is created when sealing a comic book in a bag with a backing board. Therefore, we were not able to confirm our hypothesis that a comic book will deteriorate more quickly if the phenolic acid is not absorbed.

Now let’s look at the results of TAPPI T-401 (Fiber Analysis);

E. Gerber Half-Back

Bleached Kraft Softwood 12.1%
Bleached Kraft Hardwood 55.9%
Groundwood 32%
Unbleached Kraft Hardwood 0%

BCW Comic Backing Board

Bleached Kraft Softwood 9.6%
Bleached Kraft Hardwood 90.4%
Groundwood 0%
Unbleached Kraft Hardwood Trace

Bill Cole Thin X-Tender

Bleached Kraft Softwood 17.2%
Bleached Kraft Hardwood 61.1%
Groundwood 21.7%
Unbleached Kraft Hardwood 0%

SBS is stabilized paper board, meaning that it is made using a chemical process (also known as bleaching) where the lignin is removed from the pulp. This process does leave some residual acid in the SBS from bleaching and a buffer of calcium carbonate is added to stabilize the sheet. The paper mills have a target pH level of between 6.5 and 7.2 which means that the lower the buffer the less residual acid that remains in the paper. Bill Cole Thin X-Tenders and E. Gerber Half-Backs and Full-Backs are made of VAT board which has a coating on both sides that is bleached, but the core of the VAT board is made using mechanical pulp and contains lignin. The reason that this is important is that the lignin will eventually break down and the board could become acidic depending on how much calcium carbonate is in the board and how much phenolic acid is released.

There is between 32% and 21.7% Groundwood in the E. Gerber Half-Backs and Bill Cole Thin X-Tenders respectively. Because Groundwood contains lignin, the VAT board requires a greater Alkaline Reserve to remain stable. Note that the Alkaline Reserve of the E. Gerber Half-Back is greater than that of the Bill Cole Thin X-Tenders. This is because there is more Groundwood in the E. Gerber Half-Back and therefore requires more calcium carbonate to achieve roughly the same pH level as the Bill Cole Thin X-Tender.

Attached are copies of the documentation that we received from the laboratory for your reference.

Chicago Paper Testing Laboratory – Report 45892

Chicago Paper Testing Laboratory – Report 45892- DATA