Installing and Configuring the Plugins
The heart of our workflow here, Calibre itself aside, is a pair of
plugins contributed to the Calibre plugin database by JimmXinu. In
order to use the plugins, we need to first install them. Within
Calibre, navigate to the plugin menu by clicking Preferences ->Get
plugins to enhance calibre, as seen in the screenshot above.
The User Plugins menu is, by default, sorted by the date the plugin
was added to/updated in the database. Click on the Plugin Name column
to sort by name and make locating our two plugins easier. Once sorted
by name, scroll down until you find EpubMerge and EpubSplit, like so:
Select one and then click the Install button. Click Yes when the
security risk dialog box pops up. In the next step, the plugin
installer will ask where you want links to the plugin to appear. By
default, it will add a button to your main toolbar. Because we tend to
work frequently from the context menu, we also added a context menu
As noted at the bottom of the window, you can always go into
Preferences -> Customize the toolbar to change these settings later.
Once you’ve made your selection and hit OK here, it will remind you
that the changes won’t take effect until you restart Calibre.
Click OK instead of Restart as we need to install the second plugin.
Repeat the exact same process for the second plugin. Double check that
both EpubMerge and EpubSplit are installed. Restart Calibre.
After you’ve restarted Calibre, either right click to access your
context menu or navigate to the main menu bar. EpubMerge has a few
basic configuration options, whereas EpubSplit is configuration free.
When you select Configure Plugin under EpubMerge, you’ll see the
This is the default configuration and, unless you have a pressing
reason to do otherwise, we suggest leaving as it is. Preserving the
Metadata makes it extremely easy to precisely reverse the merge at a
later date if you need to return the documents to their original
Splitting Your Ebooks
When it comes time to split your ebooks, there is the ultra-super-easy
way and the slightly trickier way. If you are splitting a book that
you previously merged with EpubMerge (and you had the “Keep Unmerge
Metadata” box checked in the plugin options), then it’s a snap to
split the mega volume apart.
In the case of our massive Jane Austen anthology, all we had to do to
turn the mega volume back into the individual books was to right click
on it and select EpubMerge -> UnMerge Epub. Afterwards, the plugin
created a new entry for each distinct book, dumped the old metadata
back into it, and placed the individual novel as an ePub in the
directory. Thanks to the preserved metadata, it’s that easy.
RELATED: How To Use Calibre To Correctly Order Your Ebook Series
If you’re splitting a document that does not have the metadata
preserved by the EpubMerge plugin (either because you have the feature
turned off or the document wasn’t created by the plugin in the first
place) you’ll need to get your hands a little dirtier. Let’s take a
look at our Jane Austen anthology using the EpubSplit plugin. After
selecting the anthology and clicking EpubSplit, we’re presented with a
fairly messy look at the guts of the ePub:
There is no automatic way to split a document that isn’t tagged with
the helpful unmerge data placed by the EpubMerge plugin, so we’ll have
to do this by hand. In the case of this already merged anthology, we
have two sets of information we can go off to guide our split. First,
each separate document that was originally merged into the mega volume
has a unique number identifier found in the HREF column (in the case
of the first novel, Sense and Sensibility, every file belonging to
that novel is tagged with the number 9781411433144).
Alternatively, if we were working with a document that did not have
clean demarcation via serial number between the different sections, we
could look at the Table of Contents column to see where each portion
(as marked via the ePubs table of contents structure) started and
stopped. We could further confirm these points in the text by hovering
over the list entry to preview a portion of the first page.
Either way, once we establish what we wanted to manually extract from
the ePub, we then highlight just those entries and click New Book. You
will receive a warning, just like you did with the Merge function,
that indicates a new entry has been created in Calibre but will not be
populated until you review the metadata:
Also like the merge process, the metadata is pulled from the original
document (in this case, the anthology) and applied to the extracted
document. In the absence of preserved metadata, you have to enter it
manually (or use Calibre’s metadata scraping function) to properly
populate the new documents metadata.
Let’s take a peek at our freshly extracted book:
The table of contents has survived the extraction process, as well as
the formatting of the novel. Another success!