Remove background picture when signing

[SoftSkilld]

Hi experts,

I have a new issue: I am using a single master page and there I have a picture field that contains (embedded) a png with the word "draft". I'd like to hide this field or picture, once a certain field gets digitally signed (this is an interactive form of type SIFbA). But trying several ways to write the script at the event postSign of the signature field didn't yield the masking of the field or at least clearing of picture.

The signature field is setup to disable input once it's signed (lock all fields in document after signing).

I tried several scripts to no avail, resigning to reference the page hard coded to be sure I'm doing it right: xfa[0].form[0].pageSet[0].Page1.DraftPic.presence = "hidden"