Pasting Text Tags in PDF document for signing - SIgnature is superimposed over Text instead of replacing it

Hi,

I'm using OneSpan's workflwo integration with Laserfiche to automate sending documents for signatures.

I'm pasting text tags in the document to be signed, then my workflow sends it to onespan for signature. This works fine on MS word documents. I paste the text tags shown below, in the word document and the tags are replaced by the correct values.

I tried the same approach with a PDF file, by pasting the text tags into text boxed on the PDF, then sending for signature. The PDF is returned with the signature and tag values populated correctly, however, it does not replace the text tags, it just superimposes the values on top of the tags which are still visible in the PDF.

I'm obviously doing something wrong on PDFs. Is there a way to imbed the Text tags in a PDF document that will result in the Signature and tags values overwriting the tags so they are not visible in the signed PDF? 

{{esl:Signer1:Signature:size(200,50)}}

{{esl:Signer1:SignerName:size(200,50)}}

{{esl:Signer1:SignerTitle:size(200,50)}}

{{esl:Signer1:SignerCompany:size(200,50)}}