Originally Posted by Ninjamitch
By he looks of it here, you have two things going on. Either the paper you are using is too thin, or you'll need to have a bit of a longer shutter speed to blow out the background more. The upper part you have there, where your plate is, is showing a yellowish cast to it. I'm assuming you can see through it....
While in Av you should be able to bump up your exposure using Exposure compensation real fast and easy. Those are those lines at the bottom of your viewfinder or in you LCD at the top or on the. Ack of your menu screen, should be about 18 of the in all which represent small increments of adding / subtracting shutter speed. Take it to the + side using your buttons.
Just realized after typing this you probably already know about exposure compensation, so sorry
The paper I'm using is about the same thickness of wrapping paper but it isn't translucent. I've tried adjusting the AEB but neither seemed to make much of a difference. I did try with flash and a high flash exposure compensation and while it did white out the background more I did get a bad glare off the marker. The yellow cast may be coming from outside the box from the office lights, I'll experiment with that when I have time. I'll post back with more detailed pictures with settings..