Re: lpi

["M. Denis Hill" <Denis@xxxxxxxxxxxxxxxx>]

> 
> lines per inch, well, i don't know exactly what this number represents
> but what is important is that this number multiplied by 2 is what the
> pixels per inch should be. I go slightly over with 200 ppi on my epson
> stylus photo because the manufacturer left out the lpi in the
> documentation.
> 

Don't know why I seem compelled to take exception with everyone this
evening, but ...

Lines per inch apply to halftone printing (as on a printing press). The
currently accepted ratio of pixels per inch to lines per inch is 1:1.5
(for 144 line screen, scan at 216 ppi at the size to be printed. It was
formerly customary to double the lpi to determine ppi at which to scan.

It now seems that many output deviced (e.g., Fuji pictrography) are
claimed to do just as well with files half of their output resolution.
Since the Pictrography machine prints at 305 dpi, there is no benefit to
exceeding 155 dpi. I have not verified this claim.

-- 
M. Denis Hill	mailto:denis@xxxxxxxxxxxxxxxx
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