On a recent location shoot where a focus chart was unavailable we
used credit cards. Where I live the credit cards have these 3-d
or hologram imprints that were great for seeing focus!!
Still, one of the BEST focus charts ever is a simple dollar bill!
Tape it up to a wall [or on top of another focus chart] and you
will love it....all those ultra tiny lines and detail make for a
great focus area...and when you are finished, you can pull it off
and buy a beer!