Quicksign signature background is not transparent white

[Seecott]

I purchased a couple of licenses of the Nitro 12.  I noticed when adding new signature to Quicksign, the signature background retain the dark/grey shade from my signature picture file.  I also have an old version of the Nitro Reader that would help remove the background dark/grey shade.  How can i g et my Nitro 12 to do the same as the Nitro Reader?  Or this is feature no longer available?

Thanks.

Edited October 19, 2020 by Seecott