Publishers and Conversion Houses FAQ

What is a conversion vendor?

Because NIMAS is not a format produced in regular print book workflows, virtually all publishers outsource NIMAS work to companies that specialize in digital conversion services. These contractual relationships are directly between the publisher and the chosen vendor and do not involve NIMAC. If you are a publisher seeking a conversion vendor, CAST maintains a self-listing page for Conversion Vendors who are looking for NIMAS work. NIMAC is also happy to provide you a list of vendors that have submitted files in the past year.

How do conversion vendors gain access to the NIMAC?

Once your account with the NIMAC is activated, the primary account holder for your company can create as many additional accounts as needed, either for others at your company, or for conversion vendors preparing files for you.

Who do I contact with questions about the NIMAS specification or creating valid NIMAS files?

Technical support for NIMAS is provided by the National Center for AEM at CAST. Skip Stahl is the primary contact for NIMAS questions and he can be reached at Resources for Creating NIMAS can also be found on the center’s website.

How do I supply my NIMAS files to the NIMAC?

Files that are under 60 MB in size can either be directly uploaded to the system, or supplied to OverDrive by FTP. Files that are 60 MB to 1 GB in size should be supplied by FTP, and those over 1 GB each should be delivered on DVD. For details on how to directly upload smaller files to the system, please review Manually Uploading Files.For instructions on how to deliver files by FTP or on DVD, please review Batch File Submission.

What happens once the files are uploaded to NIMAC?

Files must pass an automated validation process before they can be uploaded to the NIMAC. All files should be run through the NIMAC Validation Wizard before they are submitted. If your conversion vendor does not already have this tool, or if you are preparing files in-house, please contact us for a free copy of the validation tool.

Once uploaded, files undergo a quality review to ensure that the file matches the metadata, and that the metadata are complete and accurate. Information about NIMAC metadata requirements can be found at: NIMAC Metadata Guidelines.)

If the NIMAC is not able to accept a file due to problems in the file set or metadata, detailed feedback will be sent to you and/or to your vendor regarding necessary corrections.

When the file is certified, the primary account holder will automatically receive an automated “digital certificate” email confirming the acceptance of the file. You can add up to three additional email recipients for these emails, if you choose. Just contact us for assistance.

Who should I contact for technical support for the NIMAC system?

Please feel free to contact the NIMAC if you have questions or encounter a problem. If we are unable to resolve the problem for you, we’ll refer you to the technical support team at OverDrive. If you encounter a system error, you can also report the issue directly to OverDrive by email at:

Any problems experienced while submitting files by FTP, or questions regarding an FTP delivery, should be directed to the OverDrive FTP Team at