Digital BW, The Print

In a message dated 5/3/02 10:54:04 AM, david_bookbinder@... writes:

>A friend of mine has asked me to scan an old postcard she will be using
>on a
>book cover. The postcard is in black and white, on time-yellowed stock.
>It
>will be positioned at a roughly 30% angle from horizontal on the book cover.
>The service bureau wants a 300dpi TIFF file, and they are using a 150 line
>screen. I'm wondering:
>
>1. Do I need to take into account the dot pattern of the postcard somehow,
>and if so, how?

Since it is in B&W, you can scan at high res, and keep the original line 
screen, instead of having it screened anew... by correcting the white point, 
then converting to halftone with a percent threshold. You would need to 
account for the presses dotgain by adjusting the percent of the dot 
threshold, and perhaps reducing the dot size a bit more by selecting white, 
enlarging the selection (how much depends on resolution) and deleting the 
selection, to reduce the dot size.

Or you could give up on the original dots (simpler if you are not familiar 
with this stuff) and run a descreen filter as you scan, then treat the file 
as a typical continuous tone original.

C. David Tobie
Design Cooperative
CDTobie@...