Mobi is back in Vellum 2.6.2

With Vellum 2.6.2, you can (once again!) generate mobi files for Kindle. Vellum uses a new generation method that is compatible with coming updates to macOS.

To generate a mobi file with Vellum, you will need Kindle Previewer on your Mac. If you don’t already have it installed, Vellum will provide instructions the first time you generate.

Vellum will generate mobi files by default. If you prefer the new Kindle.epub format, though, that option is still available in Preferences.

This is a free update, available now.

Going Back to Mobi

After receiving feedback from our users, we’re announcing that in our next update, Vellum will return to generating mobi files for the Kindle platform.

Vellum recently moved away from creating files in the mobi format, as the KindleGen utility that Vellum used to convert these files is not compatible with the forthcoming version of macOS. To generate mobi files in a manner that works with macOS Catalina, Vellum will switch to use conversion tools bundled with Amazon’s Kindle Previewer utility.

Because we have also received some positive feedback about the new Kindle.epub files, generating Kindle-specific EPUB will remain as an option. This option will also serve as a fallback in case the conversion tools in Kindle Previewer fail in the future.

This update is currently planned for October 2. In the meantime, if you need to convert Kindle.epub files to the mobi format, you can do so by opening your file in Kindle Previewer and using the Export option. If you have any questions, please contact us.

Vellum 2.6

With Vellum 2.6, you’ll find generation for Kindle to be more secure, more reliable, and much faster. That’s because Vellum no longer relies on Amazon’s KindleGen utility to convert files to the mobi format.

Instead, Vellum will now generate a Kindle-specific EPUB file.

macOS Catalina on a MacBook Pro

Ready for Catalina

If you’ve been using macOS Mojave, you’ve likely seen warnings that KindleGen is not optimized for your Mac, and won’t work with the next version of macOS. That version is Catalina, and it’s coming next month.

With Vellum 2.6, you won’t see any of these warnings, and you’ll be ready for Catalina.

Q and A

Questions & Answers

Here are some answers to questions you might have about this change:

How do I publish my Kindle ebook?
You can upload the Kindle.epub file straight to KDP. No additional conversion is necessary. Your readers won’t see any difference in the books they receive from Amazon.
How can I check my ebook beforehand?
The best way to proof your Kindle ebook is with Amazon’s Kindle Previewer, and it’s the only way to view your book with Enhanced Typesetting before you publish. You can open a Kindle.epub file directly in Kindle Previewer.
How do I send an advanced copy to readers?
To manage your ARCs, we recommend using BookFunnel. BookFunnel can accept the Kindle.epub file generated by Vellum and will automatically convert it if necessary.

If you don’t use BookFunnel, you can export a mobi file from Kindle Previewer and send this file to your readers.

Any other questions? Contact us.

Also in Vellum 2.6:

  • You can now add an affiliate code for links to Google Play
  • Simplified approval of Restore requests for your license
  • Fixed a rare problem with incorrect page numbers
  • Improved editing margin values in regions that use a comma

To get Vellum 2.5, use Check for Updates. Or download and install Vellum from

Update 10/02/19: Mobi output is again available in Vellum 2.6.2.

Upcoming Changes to Kindle Generation

If you’ve installed Mojave, you’ve likely seen warnings about Amazon’s KindleGen utility, which has not been optimized for current versions of macOS. As those warnings inform, older 32-bit programs like KindleGen won’t run in Catalina, the forthcoming version of macOS.

We’ve received many questions about whether Amazon will publish an updated 64-bit version of KindleGen in time for the release of Catalina, due this fall. We don’t know the answer to that. What we do know is that KindleGen hasn’t received an update since 2013, and shows many signs of being abandoned by Amazon.

Given this, Vellum will soon move away from using KindleGen entirely. Instead, Vellum will produce a Kindle-specific EPUB file.

You should find this makes little difference to your workflow. When you’re ready to publish, you’ll be able to upload this file to KDP without any extra conversion; your readers won’t see any difference. To proof your book beforehand, you can open this file directly in Kindle Previewer. And in situations where you do need a mobi file (to send an ARC, for example), you can make use of the Export command in Kindle Previewer.

By avoiding KindleGen, you’ll find generation to be much faster, more reliable, and free of any warnings about 64-bit compatibility.

This change will be released in the next update to Vellum, due in early September, and well before the release of Catalina. We’ll have more details at that time.

Have questions? Get in touch.

Update 10/02/19: Mobi output is again available in Vellum 2.6.2.

Vellum 2.5.4

Vellum 2.5.4 is a minor update with the following improvements:

  • Fixed Find & Replace in endnotes, subheads, and image captions
  • Position of Uncategorized titles now matches other elements
  • All Store Links now use the https protocol

This release is a free update, available now.

Vellum 2.5.3

Vellum 2.5.3 is a minor update that includes these improvements:

  • Fixed Paragraph After Break style for sections beginning with an Alignment Block
  • Adjusted Medium-sized images so Flow options work as expected on Kindle

This release is a free update, available now.

Dark Mode

Staying up for late-night publishing? Turn down the lights with Dark Mode!

Activating Dark Mode in Vellum

Introducing an all-new, darker color scheme for Vellum. With low-brightness backgrounds and a light-on-dark editor, it’s designed to be used in dim environments.

Dark Mode can be just the thing for working at 2 AM, but we won’t blame you if you want to use it all the time!

Dark Mode requires macOS Mojave. You can activate it in the System Preferences for your Mac.

Also in this Update

  • Large Print editions are now generated into a separate folder, and won’t overwrite a standard print edition.
  • You can now use the Numbered toggle to disable numbering for Parts.

You’ll find these additions in Vellum 2.5.2, a free update. This version requires macOS Sierra or newer.

Problems with Kindle for Mac

If you attempt to proof your generated books using the Kindle program for Mac, you may encounter a few problems, especially with ornamental images:

Oversized ornamental break overlapping text

We’ve received reports of several issues with this recent update to Kindle for Mac:

  • Ornamental break images can appear oversized and may overlap text
  • Heading ornaments can disappear entirely
  • The cover image may show through to other pages
  • The Find command can show incorrect text
  • The application can freeze when turning pages
  • Links within the book can be difficult to click

As far as we know, these issues only occur when you sideload a book for testing. Books purchased by readers and delivered by Amazon should not exhibit these issues.

We’ve reported these issues to Amazon, but we have no way of knowing when they will address these problems with the Kindle for Mac program.

To proof your book, we recommend using Kindle Previewer. Kindle Previewer is the most accurate way to view your book, and will not exhibit problems like the above.

Update 1/22/20: A workaround for the image sizing issue can be found in Vellum 2.6.5.

Vellum 2.5

Announcing Large Print and more trim sizes!
Here’s what’s new in this free update:

Large Print

Now, you can create a Large Print Edition of your book with just a few clicks. Select a Large Print option and Vellum will configure everything for your book: font size, headers, page numbers and more!

With larger, more legible text, these special editions can help you reach new audiences of readers.

Mass Market

Prefer something on the smaller side? Choose from Vellum’s new Mass Market trim sizes. Your readers will love taking these portable, pocketable paperbacks on their next vacation.

International Trim Sizes

If you’re publishing outside of the US, you’ll appreciate a new set of international trim sizes. Options like B-Format, 12 × 19 cm, and A5 allow you to use European print-on-demand services, and create paperbacks in familiar sizes.

Combined, you’ll find over a dozen trim size options in Vellum!

Also in Vellum 2.5:

  • You can now customize the Outside Margin of your print edition
  • Dimensions in Print Settings can be shown in centimeters
  • Books within a Box Set can each have a Table of Contents
  • Improvements to how links and very long words break across lines
  • The use of Line Separator characters no longer results in missing text

Vellum 2.5 is a free update. This version requires macOS Sierra or newer.

To get Vellum 2.5, use Check for Updates in the Vellum menu. Or download and install Vellum from