Digital BW, The Print

After reading Roark's Lab Page on the MIS website 
(http://www.inksupply.com/roarkslab.cfm) I decided to try my hand at 
mixing ink. My first mix was aiming for 60% Grayscale. According to the 
graph on the webpage, this required 1.7% black ink (although the 
example says 2%, careful examination of the graph shows 1.7%). I mixed 
1.95 grams of MIS Photo Black with 112 grams of clear base to make 
about 3 oz of ink. It didn't seem like enough black and sure enough the 
resulting ink looks like less than 5% Grayscale. I've obviously missed 
something.

Bob