Gearset doesn't support deploying binary data during data deployments yet.
Some Salesforce objects have base64 fields which are used for storing binary data. Some common things stored as binary data are PDFs, spreadsheets, and images.
These objects have base64 fields, which means that you'll be unable to deploy them during a data deployment:
AttachmentDocumentStatic resource
If you try deploying binary data using Gearset, you will see a REQUIRED_FIELD_MISSING error message:
If you're interested in deploying binary data, please let us know by voting on this UserVoice request.