Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "lovelipp"
<arlenelove3@...> wrote:
>
> I assumed that 360 ppi was the correct resolution for my own inkjet 
> printing and for discs to send to an offset printer for inclusion in a 
> book. He says they prefer 400-600 ppi for best results. (We already 
> clarified the ppi/dpi issue). I would appreciate advice from those 
> experienced in dealing with offset printing houses. Should I start 
> saving my images at higher res? I couldn't exist without this forum!  
> Thanks so much
>               Arlene
> arlenelove3@...
> www.arlenelove.com
>

The rule of thumb for all offset printing is to have twice the dpi as
you have line screen -- i.e., 2:1 ratio. If you give the printer a
300ppi image, they'll do just fine if your offset is limited to a 150
lines-per-inch halftone screen. If you are printing images at a higher
line screen (and you should!), say 300 line-screen, then the printer
will need 600dpi images. The authoritative source for more on this is
the book Real World Scanning and Halftones by Bruce Fraser (RIP). 

If your printer is using stochastic screens (e.g., LensWork) you can
reduce this just a bit -- say to 1.5 to 1.

Hope this helps!
Brooks Jensen
LensWork Publishing