Hiding Text on 3rd Page of Multipart Form

[mredmond13]

Does anybody remember the old days when multi-part carbonless forms were used? On occassion you would have something written on the 1st page of the form that would transfer to the second, but you didn't want it to be readable on the 3rd, so they would put some kind of graphic camouflage on the section of the page where the writing needed to be hidden. The lines of the writing would blend in with the lines of the graphic and would be unreadable.

What was that called and can it be done in creating a form online?
I have an Excell spreadsheet that will be printed and made into a 3-part carbonless form. I need a blanked out portion on the 3rd page.

Any help? Thanks in advance.