Adorama QpCard 101, 3 Cards with Black / Gray / White Colors used for the White Balance System of Digital Cameras.

I looked and looked for a size when I was buying and then just decided to get it thinking it must be reasonable - but no, it is like 1 square inch and absolutely useless to me. I'm no good at returning things so I'm just out the $20.

I was disappointed with these - you can't tell how light and thin they are from the photos. They are made out of light paper. I would have gotten something more durable and not wasted money on these if I had known. When they are in the camera bag they get crumpled and damaged easily, and if they get wet (I should have known!) they turn into a soggy mess. For a paper card printed with black, grey and white paint, these are too expensive.

Up to now I used only the white part of it to get custom white balance. It is amazing how accurate the colors are! Very useful!

You might be confused (as I was) by the description referring to "a pad of 15 QPcards" but it's actually only 3 cards. That said, the cards are a good size for carrying in the camera bag, and come in a resealable envelope.

I use these cards to take a raw digital image that I can then use to get an initial color and exposure adjustment on my following images. It is small enough for my small camera bag.
I would prefer a more rugged coating, but the price is right!