QTR-Quadtone RIP

Are you referring to the ink limit in the print dialog window under advanced settings or in the ink descriptor file default ink limit setting?

If you mean the slider in the print dialog window it is just a +- % if the ink level in the quad curves. 

If you mean the one in the ink descriptor file it just means that any ink that has a limit setting left blank will use the default limit. If any ink channel has a limit set it will override the default limit for that ink only. 

Hope that helps, 
Richard Boutwell

http://www.richardboutwell.com/
http://www.bwmastery.com/