PTPT
*for quick reading, just do the words in bold
Question
I have made a greyscale tiff in Photoshop CS3 and when imported into Illustrator CS3 I have black and white rather than black and transparent. The white therefore obscures the other detail on other layers which I need to see. How can I make the white areas in the tiff transparent?
Answer
You need to work with the object in PhotoShop to create a clipping mask.
In PhotoShop, open image file.
- Note: If you’re working in Indexed Color or Bitmap mode, you’ll need to convert to CMYK or Grayscale to do the rest of this. (cannot print from RGB images. They must be converted to CMYK. And be sure that images you want black and white are bitmap for line art and greyscale for photos.)
- Using magic wand or pen tool, select the white background. Adjust the tolerance settings to something that works for your image and make sure anti-aliasing is turned on. Make sure “contiguous” is also selected.
- Select > Inverse
- Use select > modify > contract by 1 or 2 pixels to grab less of the white background …as you see fit.
- Use select > modify > smooth if necessary to smooth your path.
- Open Windows > Show Paths
- Using little flyout menu in Paths window, select Make Work Path
- Set your tolerance between .5-1.0 or somewhere in there and hit okay. The larger the number, the smoother the path, but you may get too smooth and start clipping edges off the image.
- Double click on the words Work Path in the Paths window.
- Give the path a name. Path 1 (default) is fine.
- Using the flyout menu on the Paths window again, select Clipping Path. Make sure the path you want is selected, do not leave flatness to blank or “0” (setting the flatness of clipping paths to anything less than 3 or leaving the box blank will probably result in a “Postscript Limitcheck” error. For imagesetter output (100-200 lpi screen), clipping paths in bitmap images should have a flatness value of no less than 3).
- Flatten image if it contains layers.
- Save as PhotoShop EPS.
- Choose an 8 bit preview and binary(Mac) or ASCII(PC) encoding. Leave all of the other boxes unchecked. I always use binary encoding because most of my prepress people are on Macs.
- Place the image into Illustrator. Embed it - don’t choose LINK during the place process.
- It’s in there, it’s got a path on its edge that’s acting as a clipping mask, making the background “transparent.” You can edit that path using AI’s path editing tools like smooth or the white arrow tool to drag and reposition individual anchor points. That way, if a little bit of white is peaking out, you can use the white arrow tool to snug the clipping path in a little bit.
Source :
http://en.allexperts.com/q/Adobe-Illustrator-1027/Transparent-tiffs.htm
http://graphicssoft.about.com/od/photoshop/l/blrbps_5agirl.htm
http://www.huronweb.net/file_prep.php
