Photoshop Question: Using an Alpha Channel to create transparency in a TIFF file?

Searched but found nothing specifically on this.

Problem: I have a graphic that I need to deliver to somebody for insertion into a PowerPoint Presentation. I work almost exclusively with Illustrator, InDesign and Quark, so I have no idea of file import types allowed in PowerPoint. The art director tells me they can’t handle EPS or Illustrator files in the instance, so I need to deliver the art as a TIFF.

The graphic is black and white line art (honestly it’s perfectly suited for a GIF, but they won’t accept a GIF.) Here is a copy of the graphic . I need the letters to stay white, but the remainder of the white be rendered transparent. The graphic will be inlaid on top of a gradient background, so I need true transparency.

I know that I can use an alpha channel to define transparency somehow, but I’m at a loss as to how to actually do it.

I’m using PS 7 on a Mac with OS X. I am very PS and Illustrator savvy, in fact this is the first issue I’ve ever run across that I couldn’t solve right away.

Any thoughts or assistance would be greatly appreciated.

Just to let you know…I’m running PowerPoint 2000 and I can import
Format Picture it II *.mix
WordPerfect *.wpg
Format FPX *.fpx
Postscript *.pcs
CoralDraw *.cdr
Kodak *.pcd
Portable Network Graphics .png
Mac PICT .pcz


TIFFs do not support alpha channels.

A GIF would work, if they can accept it. You might have to change your artwork a bit, since GIFs only support 1-bit masking and the edges of your image are anti-aliased to white. If you created it in Illustrator, you can just turn off anti-aliasing when you import it.

Other than that, I’m at a loss. Ponster posted several formats that would work, but you’ll have to find if they can accept them.

Sorry, Turek, but I beg to differ. In the past I have used Alpha channels in tiffs to mask selections.

Just double checked it in PS 7, and if I create an alpha channel, when I go to ‘save as’ dialog, there is an option to include alphas, just as you can include layers and whatnot.

In fact, once you’ve created an alpha, you MUST save it unless you either delete the channel or use the ‘save a copy’ option.

Nevertheless, I’m still at a loss as to how to define the white border of the image in a channel as transparent.

You’ll want to either use the wand to highlight your target or manually mask your target area, and then click “save selection” in the “select” pull down menu and save it as a “new channel” which is the default, by the way.


Some versions of TIFF do support transparency, but Powerpoint doesn’t seem to properly support TIFF transparency like Photoshop does. The transparent areas just turn gray in my version of Powerpoint.

As **Turek[/p] points out GIF transparency isn’t perfect. Powerpoint does support 24-bit PNG files though, and the transparency works pretty well. I just tested it by downloading the OP’s graphic, deleting the areas intended to be transparent, and then saving as a 24-bit PNG (use the “Save for Web” function). It came into Powerpoint looking perfect. I’m using Photoshop 7 on a PC and Powerpoint 2002.

Another option is the EMF or WMF formats. They are vector files and they do support transparency. Both of them work for this purpose in my version of Powerpoint. One note of warning though: The onscreen appearance of these formats tends to be a little rough (no anti-aliasing it seems), but they print nicely.

The one thing that really has me wondering though is why can’t they accept a GIF file? That just doesn’t make much sense to me. . . Powerpoint handles GIF files just fine, and it’s not exactly an exotic format. Did they explain any further about this? It makes me think that they may not be very savvy with their software.