A companion User's Guide is available from the KKBC home page, which details in the usual sketchy technical outlines how to use the program, so I won't go through that here, but suffice it to say that the user guide isn't really necessary, since there's very little that you'll need to learn to use this thing, and most of it is fairly self-explanatory from a cursory glance at the menu bars and buttons; a half dozen random clicks will teach you all you need to know in fifteen minutes.
I ran a quick and dirty test to see how the program fared, and for the most part I was pleasantly surprised, although not without a healthy handful of caveats. Foremost of these right from the get-go is the lack of support for epub as an input source: KBC only accepts PDFs and image files, which means that if you have a nice layout to export from InDesign your only option is to make a PDF and start over from there. You can import pages with text embedded and create text pop-ups to cover them up, or import image-only pages and create both the base text and magnified text from scratch, and then move it around and size it all to fit. If you cut and paste text from another document any styles applied in the original will not transfer, since the underlying CSS will not be copied as well, but any tags you've added to the code still will be in the HTML, so you can manually add the CSS rules to the KBC file easily enough. This, of course, implies the need to delve into the underlying code, which somewhat defeats the point of using a program such as this. But that's the last we'll see of that necessity if you actually want to add some style to your work.
Unfortunately, even though you can add text as a separate layer in KBC, the "childrens" book-type that is automatically added to the output OPF renders the text inactive in the Kindle readers, so that dictionaries, highlights and word search will not work, rendering it essentially the same as text embedded in the image. This is why I discourage the use of a book-type value in fixed layout files as a general rule, but that's a choice each content creator must make for themselves. You can, however, delete the book-type entry from the OPF manually and all the text will then be active. Why Amazon has crippled this ability in children's books and comics is beyond me.
Other detracting factors against using KBC for anything but very simple projects are its lack of an Undo button (!), so you better be sure you want to make a change before you do, because there's no way to get it back once it is gone. You can "re-link" a base text box to a pop-up, but this deletes any other custom changes that you've made to the pop-up, replacing them with the default text, and that change cannot be undone, so whatever you had created will be lost. This is a horrendous oversight on the programmers' part, and truly unforgivable in this day and age.
Even though you import images of a given size (that you have no doubt chosen for a reason), KBC will automatically re-size them to a seemingly random dimension of its own choosing, over which you have no control. In my sample test file, for example, all my images were 1118 by 1788 in size. This was chosen as the largest size for which I could achieve the highest quality setting in Photoshop and still come in at just under the "standard resolution" image file size limits the Kindle has in place for older devices (which KBC apparently does not support - only the Fire devices are listed as supported, and available for previewing). At any rate, KBC arbitrarily assigned a landscape layout page size of 1920 wide by 1535 high for my test project, making each half page image only 959 by 1535 rather than 1118 by 1788. Curiously, however, the auto-generated "scaled-images" folder contained both the original, unchanged images, as well as "thumbnail" versions scaled to 625x1000 pixels and compressed to down around 100 kb in size, rendering them utterly atrocious in quality. Which ones the reader will see is anyone's guess, but since KBC files are apparently not compatible with the eInk devices (even though those devices do support fixed layout KF8 files) my guess is that the larger ones will be delivered to the Fire devices and the smaller ones to Android and iOS apps for phones. But I'm only guessing there, so don't quote me.
You cannot open mobi files that were not created using KBC, even if they're KF8 format children's book-type files. So KBC can import a PDF but not it's own native KF8 format. Go figure.
Other than that you have the basic bold, italic, underline, and four standard text alignment options to choose from, and nothing else. There is no way to wrap text around images as in iBooks Author, or even to automatically align text boxes to a standard margin without resorting to advanced CSS editing. Text boxes can be moved and re-sized easily enough by dragging on their corners or edges, but there is no ruler or grid system by which to align them. Also, unless I'm blind I'm finding no color picker to alter the background color in the magnified text boxes, so again you'll need to learn some CSS to use this tool that Amazon is hyping in their promos as being designed for those who don't know any HTML or CSS, and theoretically don't need to learn. In other words, KBC is fairly dismal as a graphic design tool, and if you're used to using Adobe products or iBA for your layout work you'll feel as if you've been drugged and had your arms chopped off while trying to produce something genuinely inventive here.
There is a Console panel available that shows the log file which Kindlegen produces during conversion, but if you're advanced enough to understand that you don't need to be using this kid's toy. Honestly, I was hoping for an adult app at some point from Amazon that can create advanced layouts and complex motion graphics, but all they've given us so far are simple widgets only good for making very basic layouts. And that's probably good enough for beginners, but it's not something professional ebook formatters will ever use.
So to summarize:
- Easy user interface for a quick and simple learning curve
- Easily create magnified text pop-ups from base text
- Text layers isolated from background art (for potential live text upgrades)
- Editable CSS/HTML code from within the program
- Two-page spreads with facing pages made super simple
- PDF / image input for really simple import most users can manage
- Generates the necessary file structure, including OPF & NCX, which can be edited externally
- No epub or mobi file input
- Cannot edit mobi files not originally created with KBC
- Very limited layout and formatting tools
- Only basic text interactivity (pop-ups) without advanced HTML/CSS coding skills
- No support for eInk devices (exports only to "Fire-compatible" KF8 according to the guide)
- Auto-Orientation not available (locked to landscape or portrait)
- Auto-resizes images without your input (cannot select your own "original-resolution" value)
- No Undo!
- Previews only available for Kindle Fire devices currently
- Did I say No Undo?
A few notes for the more advanced users:
There are a couple of new "ke-" prefixed entries in the metadata section of the OPF that are interesting:
<meta content="doublepagespread" name="ke-layout-type"/>
<meta content="start-right" name="ke-start-side"/>
<meta content="true" name="ke-hd-images"/>
The first is what allows two pages to be knit together into one page spread or a single image to be spanned across two pages, but I haven't had the chance to dive into the generated CSS to see what's being done just yet to know what all the options are, or why this is necessary when the KF8 code already has the ability to create facing pages from two images. In this case it's a two-page spread consisting of two individual images, so "doublepagespread" is the value. The value is for a two-page spread made from a single image is, not surprisingly, "singlepage".
Second up we have the "start-side" which for the first time allows a Kindle fixed layout file to have a single standing first page on the right side (or presumably left in rl-horizontal writing mode ebooks). Previously this was attempted with the page-id "layout-blank" value, which never worked correctly, and single pages always appeared centered in the viewport rather than to one side or the other.
Finally, we have an "hd-images" entity that I presume is part of the new "standard resolution" versus "high resolution" image distribution for old model versus HD devices. Here the value "true" tells me that only the HD images are going to be transferred to whatever device the file is destined for, regardless of the model. Or perhaps it means that only HD devices are supported for this file, as implied by the absence of any mention of eInk screens in the documentation. But if "false" is also a legitimate value for this entity it begs the question of just what the heck is going on here. Of course, each of these is generated automatically by KBC, so you really aren't intended to alter them outside of the settings found in the program menus, and there isn't one for this third entry. But here they are for what it's worth.
Incidentally, KBC only produces a toc.ncx rather than a nav doc with landmarks, and the OPF contains none of the EPUB3 additions that had previously been implemented in KF8.
Well, that's all I've got for now after a quick first look. I'll ponder on it more and maybe play with it a bit tomorrow. But I doubt I'll ever use it much, except for previewing my HTML/CSS code on the fly. And honestly, that's the best use I can see right now for this thing.