QTR-Quadtone RIP

Hi all,

I have been using the Quadtone RIP to get rid of the green color cast that appears sometimes 
when printing with the standard Epson driver on my R2400. I am printing on Hahnemuhle 
Natural Art Duo matte paper and am using the profile provided on the Hahnemuhle website. 

My problem is that my files on screen are not matching my prints and I usually have to 
darken them by -10-20 in Levels to get a good looking print. In the Quadtone driver I have 
just been selecting one curve--"Velvet Fineart-Neutral". 

I looked through the user guide and there seems to be a lot more to using Quadtone RIP. Do 
I need a spectrometer for making custom profiles for my paper? It seems I am supposed to 
be making my own curves? Is it not possible just to select the neutral curve and have good 
looking prints? I mean the RIP is working in the sense that it takes away the green cast and 
makes better gradations of tone in my prints than the Epson driver, it's just that I always 
have to darken my images. What is going on?

Thank you!

Davin