Printing lineart/bitmap images

[Amitai Sandy]

Hi
In the past when I have scanned images in bitmap/lineart mode at 300dpi and sent them to offset printing, they came out pixelated.

I was told that if you scan bitmap at 800dpi and save as EPS, the printed image comes out "streamlined" without visible pixelation or raster.

Can anyone verify that?

Thanks.

[don Arnoldy]

I was told that if you scan bitmap at 800dpi and save as EPS, the printed image comes out "streamlined" without visible pixelation or raster.Well, that is a simplification, but essentially true.

If you create a 1-bit scan of line art at the resolution of your output device, it will then be as smooth as vector art output on the same device. The file will (in most cases) be much larger. You never need more than the resolution of your output device.

If you are using a high-resolution output device (2540 or 3000dpi) there is no need to use such a high resolution for your scan, since mopst people won't be able to see the difference--and the file sizes become unmanageble.

Somewhere between 600 and 1000dpi is where you want to be. Best way to know is to run a test using your particular output device. Compare the quality of output and the file size, then decide.

[Steve Rindsberg]

Saving a scan as EPS will have no effect on whether it pixellates or not. It's the same image as in a TIFF or other format, just explained in a slightly different language. It's the resolution of the image ... how many pixels you scan ... that matters.

Simply scanning at any particular dpi setting isn't enough either. If you scan a 1" drawing at 800 dpi and reproduce it at 10", it won't work. You need to know how large the original is, how large it'll be reproduced and the ideal DPI for the reproduction medium. THEN you can work out the ideal scan resolution.

Never easy, is it? ;-)

[Amitai Sandy]

Ok, thanks guys!