>With these scripts you can keep Helper Lines!
>http://kyticka.webzdarma.cz/3d/moi/#KeepCLine

Indeed, as I mentioned in the first post, those were one of the first set of scripts I installed when I started testing MoI. Essential for the way I like to work.

My question was more regarding the specific UX design strategy behind Michaels decision not to implement permanent construction guides as a standard function. Most of the 3D design packages I've used over the years enable the user to implement some form of construction guides but seeing as both Rhino & MoI don't provide that functionality as standard I suspect there must be some kind of reasoning behind the decision. If I were to guess, it would be that the very nature of Nurbs modelling (fundamentally being about boolean operations and cutting elements away via trimming surfaces and such like) lessens the need for permanent construction guides. Whether a curve is drawn as a guide or as a base element to an e.g. trimming surface isn't really relevant but all those curves can be used as aids whilst modelling. That's my guess anyway but I'm probably way off the mark! :)

jm