Create empty signature field
PDFBlackbox allows to create empty signature fields for later signing. Empty signature fields can be added in the same way as regular signatures (see the corresponding how-to article), but TElPDFSignature.EmptyField property should be set to True. Empty signatures can be both visible and invisible. You can create multiple blank fields in one document.
The number of empty signature fields in the document is specified by TElPDFDocument.EmptySignatureFieldCount property. Empty signature fields can be accessed via TElPDFDocument.EmptySignatureFields property. Each field is represented by a TElPDFSignatureInfo object that contains basic information about the field, e.g., its name, mapping name and position.