[Biolek]

1.I readed that for screens between 230-305 and higher I must use proces inks or reduce the "cheeper" plastizol ink.What would be the best choice?Because I want have a thin print.

2.For haltones and vector prints can I use 230 mesh?.Or will be better 305 mesh for halftones and 230 or smaller for vector?

3.And what is the best working resolution?Because some recommend 300 dpi some 200 dpi.

My vector image

Halftone image:

 

[PositiveDave]

Rule of thumb:
lpi = screen mesh/4.5 (ish) imperial.
You can, for example, use waterbased inks for a light hand.
Resolution, if you have a 200dpi image and a 50lpi halftone, each halftone cell only has 17 shades of grey! You get postscript banding. At 300dpi it's only 37 shades. It will look posterised. Use a RIP if you can, try Ghostscript.

 

[Spot_Worker]

Hey dave for those who read this later. Talk about postscript banding, and posterised. What they are and what they look like. So, the new start ups....have some of the words down.
Thanx

 

[PositiveDave]

If you have a gradient, it should be a nice smooth transition, if you are limited in greyscale you will see a series of different shdaded bands across the gradient.
Posterising is just reducing an image to a few colours.