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.

Where do I go for guidance on 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 All files must be tagged in accordance with the NIMAS 1.1 Specification and the DAISY Structure Guidelines. These and other resources for Creating NIMAS can be found on the center’s website.

What is the NIMAC Validation Wizard?

The NIMAC Validation Wizard is a stand-alone Windows program that provides DTD validation for NIMAS file sets. It also ensures that the XML is well-formed and that all referenced images are present in the images folder. NIMAC requires that all NIMAS files be validated using the tool before they are submitted to the NIMAC. The tool is available for free download from the NIMAC system to all publishers and conversion vendors. If you are a new publisher or vendor and do not yet have an account, please contact the NIMAC and we can provide you with the set-up file.

Am I required to supply title metadata for NIMAS file sets?

Yes. In order to be accepted into the NIMAC, all files must be accompanied by the required OPF metadata. Please ensure that you follow the NIMAC Metadata Guidelines in supplying the OPF metadata for each file set. Files delivered by FTP or on DVD must also be accompanied by a metadata Excel sheet for the delivery.

How do I supply my NIMAS files to the NIMAC?

Files up to 300 MB in size can be directly uploaded to the NIMAC system by logging in and using the Add Inventory option. Due to upload times, however, we recommend that files over 200 MB in size be delivered by FTP. There is no minimum size requirement for supplying files by FTP. However, files over 1 GB in size each should be delivered on DVD.

If you do not have an FTP login for the publisher, send your NIMAC login ID and a request to have an FTP folder created to:

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.

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