[curstpriest]

Sounds like you just don't understand the technology or are expecting something different. It's not black on white, but it's close. If you go to k1 it's less close. If you're unhappy with k3, you'll be much less happy with k1, and slightly less happy with k2.

There really isn't any difference between exchanging them either.. These things pass QC so it's not like your particular model is defective, it is what it is.

The only things that really affect the contrast are:
1) your brain (and to an extent your eyes and the optic pathway) - if you are using the white model, it lowers percieved contrast, the graphite model will give you higher perceived contrast.
2) ambient lighting - look at it in the sun, or quality fluorescent light (3ft). Don't use tungsten light sources, or low light environments. Lower brightness = lower contrast.