overprint

[steven]

Hi, I created a logo (black text only) in corel draw and saved it as a
picture. I imported this picture to publisher 2003. When i turn my
publication into a pdf file for commercial printing (CMYK) the is a white
outline around every letter of the logo. The logo is in fron of gray
backgound.

I did a little reading and figured this must be an overprint issue. I tried
manyally setting the logo to overprint using tools>commercialprinting
tools>registration settings>per object and clicked on overprint. I try to
turn the pub into pdf agian but nothing changes. The white outlining is still
there... what sould i do?

Steven.

 

[steven]

I do not remember. It must have been a .png file. I don't have the original
file just the one inserted in my pub. Can the file format be checked from
within the publication?

and it must be an overpint error, what else can it be?

S.

 

[Ed Bennett]

Hi, I created a logo (black text only) in corel draw and saved it as a
picture. I imported this picture to publisher 2003. When i turn my
publication into a pdf file for commercial printing (CMYK) the is a white
outline around every letter of the logo. The logo is in fron of gray
backgound.

I don't think this is anything to do with overprinting, personally.

What image format did you use when you exported your picture?

 

[Ed Bennett]

and it must be an overpint error, what else can it be?

PNG is a raster file type. You've gone from a line drawing of the font
to an image composed of pixels. To make this look smoother, where edges
cut pixels in two, CorelDraw does a clever little trick known as
antialiasing - it makes the pixels a shade of grey in proportion to the
amount of black there is 'in' that pixel (or there would be if you could
image the line on a sub-pixel level). (Note that it's only black for a
black and white line drawing.) Now, if you set the transparency to be a
white area, then the lightest of greys will still appear light grey, not
transparent. This will give you a whiteish haze around your image.

If you were using JPEG, the effect would be exacerbated by JPEG artifacting.

The problem is also hindered by the fact that Publisher doesn't properly
support PNG transparency, so you may or may not get the entire rectangle
of the PNG file filled in white rather than being transparent.

The solution to all these problems is to export from CorelDraw as an EMF
file. This is a vector file, so completely bypasses the issue of
pixelation and antialiasing. Plus, you get theoretically infinite
resolution - only limited by the resolution of the printer (try zooming
in on the PDF file - you should get smooth lines all the way in to 2400%
zoom, whereas with the PNG file you'll get pixellation at a few hundred
percent).

When EMF doesn't work, the next step is to try WMF. However, this
doesn't often work as CorelDraw's WMF output isn't terribly friendly
with Office programs. Failing that, I would add a coloured rectangle
behind your line art in CorelDraw in the same colour as the background
in Publisher, then save that as a PNG. That means the antialiasing will
be the same colour as the Publisher background, removing the white fuzz.
Plus, if Publisher's transparency breaks, the image edges should still
blend nicely into the background.

Hope this helps!