I saw a photographer several years ago use a large 18% gray card in every shot she took. My wife and a few of our dogs earned some titles at the event and paid to have several photos taken.

When we received the photos it became clear what the blank gray card was for. First she could use the gray card to get the exposure correct at the shoot. In Photoshop the gray card can help set levels more accurately. And best of all, it gave her a nice "pallet" to add the correct text and titles in post production including the official logo of the sponsoring club.


It seems like a great idea. No letters to carry around and no panicky setup time between takes.