Hey Mike, I must admit that when I first read your post, I strongly disagreed with you on this one. But it was on my mind all day at work and the commute home. Then it clicked while sitting on the couch. I thought back to our previous post about the 3155. Then I thought about conversations with Ken's people in the different sections of Badger and Scott Craig's website. Yes, you are very good at what you do, but most hobbyist don't think on that level of the dynamics of it all. So here's the deal as told by me. It all depends on what you are used to. I grew up on Badger's 100 series type heads, XF, IL, and HD now known as fine, medium, and large. Modeler's, for the most part, only use one type of medium. Yes, there are variations of viscosity and such, but they are all relatively thick as compared to inks and dyes. So, given th same medium, same viscosity, and same pressure, you will see a vast difference in line width from different size tips and nozzles in the traditional illustration or "detail" brush. However, if you decided to mix and match the needle/nozzle combo and swap mediums, the extreme tapered needle would still be capable of fine lines per se, but the weight of the line would come into play as the nozzle size would determine the amount of fluid ( based on viscosity ) released for the spray. Now to prove all of this? The Iwata Eclipse BCS. Although it has a .5mm cone nozzle, the needle taper will allow it to go from HAIRLINE to 2 inches. However, hairline can only be achieved with the proper medium and air pressure. No way is Pactra R/C paint going down as a hairline because you have to push to much air to move the paint. The next thing that comes into play is the ability of the user to maximize the capabilties of his brush, but that's another conversation for another day.
No disrepect to anyone on this board in any way, shape, or form, but the finest airbrushers that I have had the pleasure of conversing with personally are Tom, Mike, and Scott. Thanks guys, I'll keep learning from ya!
E