Digital BW, The Print

Using K3 Ks alone with QTR, when linerazing the ink set I get banding 
in the first 0-4%. Once profiled, the grayscale does not show the 
banding any longer. It's not a hardware issue, two 4800 do exactly the 
same.

I know the K3 are too "dense" to show smooth hilghlith values, but I'm 
very puzzled at seeing that QTR-ICC solves the issue. Any idea about 
what's happening ?

Olivier