Hi Hugo,
You may able to suppress the field itself
Right click the field > Click FORMAT FIELD > Click the COMMON TAB > If there is a FORMULA BUTTON to the right of SUPPRESS click it
Enter the above formula > IsNull({YourBLOBField})
or
you have to put each in its own section then suppress the section with
1. SUPPRESS BLANK SECTION
2 - Suppression formula IsNull({BlobField})
Yes you have add more fields based on page setup(landscape). And hide the blob field is not possible used the above suppress formulas based on data display.
Regards,
DJ