The pixelizing can be pretty tricky, sometimes you won't even see it XD It's really hard to see when there's too much/not enough sharpening/smoothing. I've got some problems with it myself.

As for Clara, you might have tried plain old white with different fonts, or multiple colors. Or on a black stripe. Or just without any text. Don't hesitate to experiment a lot :) Also, the Clara in the lower right corner is a pixel lower than the others (there's a small stripe of black on the top of her square) :P