Thank @mkl, using your test code testCreateSignatureWithMultipleVisualizations I could have a better approach for my requirement to add multiple signatures to one document. But I my case I need to use saveIncrementalForExternalSigning(signature) method to sign the document externally and unfortunatelly I got the exception "Can't write signature, not enough space". I resolved this exception by creating new SignatureOptions to setPreferredSignatureSize() but somehow in the signed document, there only last signature was displayed, the others were hidden. I will be very grateful if you can give me a hint on this issue.