HiL; set it as a watermark on your slide master....
http://office.microsoft.com/en-us/power ... 41033.aspxAdd a transparent background
Open a blank PowerPoint presentation, or a completed presentation to which you want to add a background.
NOTE If your completed presentation contains master slides, you might not want to apply the background to the master slides and risk unwanted changes to your presentation. The alternative is to add the background to one slide at a time.
To add a background to all the slides in a blank presentation, point to Master on the View menu, click Slide Master, and perform the following steps on the slide master. To add a background to a single slide, simply select a slide and follow the same steps.
Choose the logo or clip art you want to use as a slide background. On the Insert menu, point to Picture, and then click Clip Art to create a background from a new picture, or click From File to use a picture you have in your files.
Keep in mind that not all clip art makes an appropriate background. You might have to experiment a little.
Select the logo or clip art you want and insert it in the presentation.
The logo or clip art appears on the slide master, but is not yet transparent.
Right-click the logo or clip art on the slide, and then click Format Picture.
On the Picture tab, click the arrow next to the Color box, click Washout (Watermark in PowerPoint 2000), and then click OK.
With the logo or clip art still selected, right-click and then click Save as Picture. Save the image where you can find it.
Delete the original image from the slide. You'll replace it with the transparent version you just prepared and saved.
On the Format menu, click Background.
In the Background dialog box, click the arrow in the box under Background fill, click Fill Effects, and on the Picture tab, click Select Picture.
Find and select the picture you formatted as a transparent background, click Insert, click OK, and then click Apply.
Your transparent image has been added to the master slide as a background, and the new background will appear on every new slide you add to the presentation. If you selected a single slide, the background has been added to the slide you selected.
Add a watermark
Open a blank PowerPoint presentation, or a completed presentation to which you want to add a watermark.
NOTE If your completed presentation contains master slides, you might not want to apply the watermark to the master slide and risk unwanted changes to your presentation. The alternative is to add the watermark to your slides one slide at a time.
To add a watermark to all the slides in a blank presentation, point to Master on the View menu, click Slide Master, and perform the following steps on the slide master. To add a background to a single slide, simply select a slide and follow the same steps.
Choose the logo or clip art you want to use as a slide background. On the Insert menu, point to Picture, and then click Clip Art to create a watermark from a new picture, or click From File to use a picture you have in your files.
Keep in mind that not all clip art makes an appropriate watermark. You might have to experiment a little.
Select the logo or clip art you want and insert it in the presentation.
The logo or clip art appears on the slide master where you will make it transparent.
Select the logo or clip art on the slide, and on the Right-click menu, click Format Picture.
You might want to change the size of the picture as it appears on the slide. On the Size tab, under Size and rotate, increase or decrease Height.
To center your picture on the slide, on the drawing toolbar, click Draw, click Align and Distribute, and then click Relative to Slide.
Click Draw again, click Align or Distribute, and then click Align Center and Align Middle.
On the Picture tab, click the arrow next to the Color box, click Washout (Watermark in PowerPoint 2000), and then click OK.
At this point, you can either place the watermark in the background of a slide that already has text, or you can add text to the slide or slides.
When you are done editing and repositioning the watermark and are satisfied with its appearance, to send the watermark to the back of the slide, right-click it, point to Order, and then click Send to Back.
NOTE After you send it to the back, you can no longer edit or reposition the image.