A trick that usually works is to turn on all the table's borders
(Format Borders & Shading) and color them white. That will hide the
gridlines if they're turned on, but will be invisible unless the
person has set the window background color for all Windows programs to
something other than white. (I happen to be one of those people. g)

Sneaky!! I'll do that, too. Been fooled more than once by invisible =
(white bordered) tables...

Greetings,
Klaus