transparent background not working right

[mJ]

Hi I have a logo in CMYK colors, 300 dpi in tiff. format set for commercial
printing. The problem I'm having is that i import it,
then i go to the set transparent icon and the white background becomes
transparent. The problem though is that even the white lettering becomes
transparent. I've cut and pasted the logo it to a transparent background
through photoshop but there is still a white background when I bring it in
publisher. How can I make my logos background tranparent without making the
letters transparent?

 

[Ed Bennett]

Hi I have a logo in CMYK colors, 300 dpi in tiff.

If I were you, I'd avoid using CMYK TIFF files in Publisher. Publisher
converts them to RGB on import (destroying, among other things, your
transparency), and then back to CMYK on output (if you're using
Publisher's CMYK tools; otherwise, it prints as RGB but your printer
converts back to CMYK). If you use an RGB file, then there's only one
conversion (when you print). One conversion is better than two, as you
get half the quality loss inherent in the conversion.

I have little experience with transparent TIFFs in Publisher. I know
that transparent PNGs will display correctly but not always print
correctly. A workaround for that limitation is either to export as a PDF
(Publisher 2007 only) or to save as an image (Publisher 2003 and 2007).

 

[Dominic Martin]

Ed is right, with TIFF files you're better off starting with an RGB, rather
than a CMYK TIFF.

When you use the transparency button, you're telling Publisher to make all
pixels with the RGB value that you clicked on transparent. So a white pixel
(RGB 255, 255, 255) will become transparent, wherever it resides in the image.

The solution with TIFF files is to use the Alpha channel. In a program like
Paint Shop Pro or Photoshop, you can create a mask around the image. The mask
is set to hide the portions of the image that you want to be transparent.
This mask information is stored in the Alpha channel. Publisher 2003 and 2007
will read this information and leave those areas transparent.

The other alternative is an EPS file. If I remember correctly, EPS files are
not converted to RGB but are left alone. They also support masking portions
of the image but I can't remember if Publisher reads those or not.

Regards,

Dominic

 

[Ed Bennett]

The other alternative is an EPS file. If I remember correctly, EPS files are
not converted to RGB but are left alone. They also support masking portions
of the image but I can't remember if Publisher reads those or not.

Word on the street is that when you use an EPS file and print to a
PostScript printer, the PostScript data is passed through unharmed. That
includes CMYK and alpha channels. YMMV, of course.