Currently, there's no good way to create lines in certificates (e.g. beneath signatures).
I’m currently using a 180px x 1px image, which renders inconsistently in both web and PDF view.
For web view, the lines are ok in Firefox but too thick in Chrome.
For PDF, the lines are ok in Firefox but too thick in Adobe Acrobat.
I tried using underscores “______” but these lines are heavily dependent on font and font size.
At certain zoom levels, they look like this “_._._._._._”