QTR-Quadtone RIP

--- In QuadtoneRIP@yahoogroups.com, "milogiacomorambaldi47"
<milogiacomorambaldi47@...> wrote:
>
> I'm still looking for heuristics for selecting the best Default Ink
> Limit.  This seems to be an important first step, but the best
> approach seems unclear.

I'd like to ask a related question.  I'm creating curves for a 2100
with Cone K7 inks.  Most of the curves that Cone supplies are
"pre-compiled".  That is, there are .quad files but no .qidf files. 
Roy supplies a .qidf for HPR for several printers.  I'm using this as
the starting point for my curves.  In this curve definition, the
default limit is set, but all the other limits are blank.  Is this
standard practice for K7 curves?  What does leaving this blank do? 
Why not specify a limit for each grey based on where the differences
cease to be visible?

Ferdinand