Comics, graphics and file sizes

A quick look at the issue of file-size in digital comics distribution and how it affects readers’ storage of their comics (and how Libreture can help)

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While working on PDF support for Libreture, I took the opportunity to look more closely at the digital comics field. A few things popped out to me time and again about how digital comics are currently provided to readers.

Graphics-Heavy titles

Ebook formats and file-sizes have remained consistent, but the same cannot be said of digital comics.

There’s a variety of comic formats, with varying quality, file-size and reader compatibility. What format comic creators and publishers choose really does have an impact on readers. The most common digital comic formats now include:

    ComicBookZip/ComicBookRar - Zipped files that contain the individual pages as JPEG files. That's it. The final letter in the abbreviation (Z/R) refers to the compression format: Zip or Rar. These files usually contain no metadata, only the images.

  • PDF
    Portable Document Format seems the perfect format for comics. Each file is a linear, page-by-page, describing visual and text elements. Again, no metadata to describe the file's contents.

  • ePub
    This common e-book format works just as well for comics. Each page contains the same JPEG that would be included in the CBZ/R file, but with the added benefit of metadata to describe the title, author and other information.

The CBZ/R and ePub files seem to share their source material, the JPEG images. The same comic or graphics-rich book in either of these formats will usually be the same or similar file size, since they're both simply zip files containing the images.

PDFs, on the other hand are getting much larger than their counterpart formats, since they're now used as the preferred 'High Quality' version by many comic publishers and retailers, such as the wonderful Humble Bundle. These can be as massive as 3GB. We’re talking big enough to want to leave them on the shop site, because who needs files that large cluttering up your digital device?

This leads us to a bit of a problem. Where the heck do you keep them?

Size is important

To support both ebook readers and retailers, I want Libreture to address the fragmentation of digital libraries.

Buying e-books can end up being a messy task, especially when you're determined to only buy DRM-free titles. You end up buying both novels and comics from a variety of different shops, as bundles or separately, sometimes even different parts of a series from multiple sellers, and it’s easy to lose track of your purchases.

That’s why Libreture started life. It creates a central library for all your digital reading material, and it doesn’t matter what size that material is – to a point. That point, of course, is cost. Storage costs money, but Libreture is designed to do this fairly. More on this in a minute.

Why ebook and comic sizes matter

Text-based e-books, in the common ePub or Mobi formats, tend to be around 2MB in size. If they're much larger than that, it's usually down to the book being absolutely gigantic or because it contains lots of inset images or a large cover image. Text is text and doesn't take up much space.

Comics, on the other hand - or any graphics-rich titles - are much larger. Everything is an image - even down to 'drawing' the text. In a digital format, a drawing of text takes up more storage space than the text itself would in another format. Compressing artwork to make the comic files smaller reduces the quality of the art, which goes against what readers naturally want – and the comic creators as well.

If comic creators avoid high-compression, the files can be extremely large. And you can see that comic publishers are aware of the issue, since they've started to increase the compression for CBZ/R and ePub files to maintain lower file sizes, while at the same time reduce the compression of their PDF files, and label them 'High Quality'. They know that readers have a variety of devices, some of which won’t cope with giant files, but that they will always want to own comics that are close to the quality that the creator intended.

Cover of Trees - Issue 1.

I have Trees #1 by Warren Ellis and Jason Howard to hand. Published by Image Comics, it was available in CBZ/R, ePub and 'High Quality' PDF formats (before Image decided to stop selling digital comics direct).

The book is 35 pages long.

ePub & CBZ: 34MB
PDF: 121MB

I zoomed into the same area of a particular page in both files. The difference was clear. ‘Artefacts’ in the compressed JPEG image files have led to poor image quality in the ePub and CBZ versions.

Interestingly, not only is the PDF less compressed than the awesome original artwork, but the format has its own compression methods that come into play at very large sizes,so even the largest PDF files are not much bigger than their ePub or CBZ counterparts.

You can find more information on how images are stored in PDF files in this article from IDR.

What’s the problem with (very) large file sizes?

You always want the very best quality version to hand, right? But downloading all your PDF editions and storing them separately is a big ask when the files can be up to 600 or 700 Megabytes for a single book! What’s worse, many portable devices simply won't open those files. I have two separate Android tablets of different ages, that are becoming increasingly useless as both apps and files increase in size and memory usage.

Comic book readers are being asked to download one format for reading immediately on older or lower-capacity devices, while downloading another, larger, file for reading on high-end or newer devices, and for archiving. This fragments your comic collection, unless you’ve got a useful space in which to lovingly keep them.

Libreture is as much for comic book readers as novel readers. It aims to provide a worthwhile storage service to comic readers, RPG fans (try getting those tomes in ePub format), and readers of other graphics-rich titles. And when I say ‘worthwhile’ I also mean ‘not making you pay through the nose for the privilege.’

Storage space-based subscriptions

Libreture is designed to give each customer exactly what they need for their book storage, when they need it.

There seems to be a growing problem with comic book storage and online collection management. Books and other digital media have become so large that they are effectively Too Big To Own, and many publishers have switched to subscription models where readers own nothing at all. None of that seems fair to me. Readers should be allowed to own the things they spent their hard-earned money on, to keep them in a convenient place, and to access them however they like.

Sustainability and fairness are at the basis of Libreture’s existence. For this reason, Libreture offers subscriptions based on storage space only. Everyone gets the same useful features, but if they need extra storage, that’s what they pay for. This way we support digital comic readers, role-playing gamers, academics, reference book readers, and many more. Anyone who reads anything, any size, can store their material on Libreture.


Open your FREE account and start uploading your ebooks, digital comics, and magazines today!

Libreture supports DRM-free PDF, CBZ and CBR formats, along with ePub and Mobi e-book formats. Give it a try, and when your Free plan is full of brilliant comics, add some extra storage that suits your needs.


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